Ultimate hevi sand

Hevi Sand presentation
SAIF 29/9/2010

AMCOL Overview

n  US-listed (NYSE:ACO); Incorporated in 1927.

n  Global leader in bentonite performance application products and services
l  Industrial and consumer end markets

n  Innovation and market driven development pipeline; Over 100 patents in
force.

n  Global bentonite mining operations.

n  Responsible corporate citizen (we understand our role in the community)

June 2010

AMCOL Global Entities

28 Operating Companies

September
2010

Excellence through research and Development
The H.S. Process (patented)

Hevi-Sand® Diary

•  WHY
•  2005 commodity boom, supply concern
for Amcol and its customers
•  2005 desire to sell Hevi-sand Globally in
all Amcol locations
•  2005 started investigating possibilities
and market size.
•  2005 started investigating process
requirements.

Hevi-Sand® Diary

•  2005 started speaking to current suppliers
re supply agreements, developments,
projects etc
•  2005 Failed to get a meaningful response
from suppliers, started looking for a
suitable deposit.
•  2005 Continued process research.
•  2005 investigated costs and likely
investment.
•  2005 investigated customer product wish
list

Hevi-Sand® Diary

•  2006 started looking seriously for a
suitable reserve. (found Batlhako)
•  2006 started doing pilot work on the new
process.
•  2006 started board approval process for a
probable US$50m investment.
•  2007 agreed purchase of Batlhako.

Hevi-Sand® Diary

•  2007 continued pilot work on the new
process.
•  2008 Bought old Paul Kruger spiral plant
Thaba to ensure continuity of supply to
existing customers.
•  2008 Continued tuning the process.

Hevi-Sand® Diary

•  2008/9 Eventually all pieces in place and
ready to go.
•  GLOBAL FINANCIAL MELTDOWN
•  2009 Board approval to build the plant.

•  2010 July commissioning new plant

Amcol South Africa

South Africa Chromite Mine Investment

ü  Feb-09: Acquired controlling interest in
Batlhako Mining Ltd, Ruighoek Farm.
ü  Initial indicated resource: 11 million tonnes.
ü  June-10: Began commissioning 100KT/A
chromite processing facility
ü  Sept-10: Acquired remaining interest in BML.

Geology of the South African chromite Deposits

BUSHVELD COMPLEX RSA

Chromite Formation

•  Crystallization is the (natural or
artificial) process of formation of solid
crystals precipitating from a solution,
melt or more rarely deposited directly
from a gas. Crystallization is also a
chemical solid–liquid separation
technique, in which mass transfer of a
solute from the liquid solution to a pure
solid crystalline phase occurs.

Chromite Formation

•  Crystallization separates a product from a
liquid feed stream, often in extremely pure
form, by cooling the feed stream or adding
precipitants which lower the solubility of
the desired product so that it forms
crystals.
•  Well formed crystals are expected to be
pure because each molecule or ion must
fit perfectly into the lattice as it leaves the
solution. Impurities would normally not fit
as well in the lattice, and thus remain in
solution preferentially

Chromite Formation

Crystal stuck together in a silicate soup

Chromite Formation
Crystals stuck together in a silicate soup

Traditional Chrome Ore – Supply Chain

MET GRADE 75% FERRO CHROME PRODUCTION

MINE CHEM GRADE 15% CHROME PLATING

FOUNDRY GRADE10%

PROCESSED BY DISTRIBUTOR

TRADERS FOUNDRIES

Recent and Historic Market Conditions

•  UNDER SUPPLY , SHORTAGES AND RUN
OUTS

•  PRICE VOLATILITY

•  VARIABLE QUALITY DUE TO SHORTAGES and
BY-PRODUCT STATUS

•  LITTLE OR NO TECHNICAL SUPPORT

•  MARKET SUPPLIED BY TRADERS

Traditional chrome sand production

Magnification of Chromite in lump form

X20

X10

Traditional chrome sand production MINE FINES

Traditional Processing Ball Mill

Traditional Spiral Processing
Traditional Processing:
Humphrey’s
Spirals – Washing
and Separation

Traditional Chrome Processing Layout

Traditional chrome sand production

•  Typically less than 3% of ROM (run
of mine) chrome ore ends up as
Foundry Sand.
•  Traditional production methods
would be financially unjustifiable
without ferro-chrome production
•  Foundry sand is a by-product for
FeCr producers.

H.S. PROCESS Plant Requirements our Conclusions

•  High Yield to be cost effective
•  We needed to understand the
impurities and there effect on casting
quality
•  We needed to remove the impurities
while maintaining chrome crystal
integrity
•  We needed low power and water
usage due to availability shortages in
RSA.

H.S. PROCESS Customer Requirements our Conclusions

•  High Quality Consistent Product.
•  Continuity of Supply
•  Price Stability
•  Local Stocking Points
•  Technical Support and Advice
•  Different Size Fractions, and Distribution
curves (permeability, and penetration control)
•  Reductions in Resin and Catalyst additions
(gas generation)
•  Better High Temperature performance (fusion)

H.S. PROCESS Market and Product Contradictions

•  Order Specifications, different everywhere
and in many cases out of date or not
achievable.
•  Test procedures, different everywhere and
very often unspecified.
•  Sampling Procedures often unspecified
•  Chemical analysis methods and
procedures unspecified and incorrect.
•  Due to the disparate nature of the market
no unification of testing and procedures
has developed

H.S. PROCESS Conclusions (yield required)

MINE
(100%)

MET GRADE CHEM GRADE REFRACTORY FOUNDRY WASTE
5% 5% GRADE 5% GRADE 10%
75%

Financial justification requirements FOUNDRY

Magnification of Chromite lump (Yield)

X20

X10

Research Utilize the whole ore body

Typical edge of seam ﬁnes


Washed and crushed Lump Fines

Silicates attached to chromite Grains


Whole Seam washed and crushed


Close up of Whole seam washed and crushed


Crushed Lumpy Unwashed

•  Wash crushed lumps classified but without
separation

The Silica is actually low melting point silicates.

Minerals

Chromite Enstatite Anorthorite Hematite Phlogopite

Others

Particle mineral map from the -1180 +850 μm fraction of the
AMCOL Chromite sample via QEMSCAN analysis.


•  Silicate type prevalence changes with
grain size

Conclusion Utilize the whole ore body

•  There is NO SILICA, all these
impurities are essentially forms or
phases of Magnesium silicates and
their prevalence is associated with
size fractions
•  They have melting points which
range from 800 – 1800℃
•  Therefore lowering the levels of most
of these impurities increases the
fusion point of the final product.

Fusion Testing 0.4% silicates at 1600c

Fusion Testing 1% silicates at 1600c

The HS PROCESS was born

•  It became clear to maximize yield
without damaging final quality
required a process which removed
the surface contaminates on the
chrome grains without damaging the
crystal integrity
•  Therefore the impurities should be
shocked from the chrome grains and
any remnants abraded away as the
impurities are not soluble.

Conclusions from Old Spiral Technology

•  We also knew from our old spiral plant,
that by removing the impurities using
spirals and water caused massive losses
and nearly all the useful fines ie up to 70%
of the feed was lost.
•  We also new the high power and water
demand, of ball mills and spirals, not to
mention the crystal damage inflicted by
the mill.
•  These factors made a modified spiral plant
impractical.

View Of Mine-workings with new plant in distance

Fluidised Bed Dryer & Refining Building

H.S. Process Silicates Separation Technology

MAGNETIC & ELECTROSTATIC SEPARATION OF IMPURITIES

Electrostats

MAGNETIC & ELECTROSTATIC SEPARATION OF IMPURITIES

Ultra Separation Plant Science

•  Electrostats •  Rare Earth Magnet

Sand Flow single Layer

Sand Flow single layer

Rotation

Rotation

+ + +

+

++ MAGNET

Magnet

Chromite

lost charge

Silicates

Slicates

Chromite
Hold Charge

Non Magnetic

Magnetic

Storage and Re-Blending of Size Fractions

H.S. Process Plant Overview

•  WET Process-:
•  LIBERATION – Rotary Impact Mill
•  PREWASH – Screening & Clay Removal
•  ACID WASHING – pH control & cleaning
•  DRY Process -:
•  DRYING – FUIDIZED BED
•  MAGNETIC AND ELECTROSTATIC SEPARATION
•  SCEENING AND DE-DUSTING
•  SIZING AND CLASSIFICATION
•  IN LINE TESTING
•  PATENTED PROCESS

Waste Product results

•  Silicates 95.3-97.8%

Ultra Hevi-Sand Product results

•  Silicates 0.3-0.8%
•  Chrome 47.5 – 49%
•  Iron oxide 24 – 26%
•  Chemical analysis
maintained afs 25 to
70.
•  Acid demand Ph 3
less than 5ml

Great Result but we had some Problems

•  PROBLEMS-:

•  Product Segregation and large tramp silicate
particles

•  Variable set times and strengths on some binder
systems

•  Inconsistent turbidity

•  Low packing density

Segregation

•  PROBLEMS-:

•  Even with in line sampling we had complaints-so
we investigated sampling

•  We had installed a low energy static blender
which we thought may have caused some issues

•  We had designed steep angle low segregation
hoppers but questioned there effectiveness

Investigation into AFS Discrepancies
Hevi-Sand Production Facility
Ruighoek, Republic of South Africa

AFS Discrepancies

•  AFS grain fineness values are
consistently reported coarser
(lower AFS)
at customer sites than measured in the
Plants QC laboratory

•  Why?

AFS Discrepancies

•  Key issues at play
The first is Segregation

refer to the video from US silica for a good overview of
segregation in bulk aggregates

AFS Discrepancies

The finer material has a tendency to flows
through first which results in some
stratification in the bag –particles segregate
based on size, shape and density
The plant has installed in anti-segregation cones
in key places as well as having 72 degree
angles on holding bins to prevent segregation
However, segregation is very difficult to
eliminate completely

AFS Discrepancies

•  Key issues at play
The second is Sampling
“Grab” or hand sampling from the top of the bag does not yield a
representative sample ( Segregation during filling suggests a coarser
sample will likely be obtained)
Sampling spears are often used to sample bulk bags of grain or sand-
given that they can penetrate at least ¾ deep in the bag and an
appropriate spear and technique is used
Some spears take samples from multiple heights via a rotating inner shaft
or sliding gate, after which the subsamples from the different heights
are combined prior to testing

Examples of Various Sampling Spears
•  Due to the hardness and
particle size of Hevi-Sand it
makes using these spears
difficult
•  If a spear has a single
unblocked opening and is
inserted in the top of the bag
it will sample material from
the top preferentially
regardless of the depth
inserted
•  Some spears are better
than others but none satisfy
the requirement of obtaining
a representative sample!

Sampling

Sampling is defined as the process of removing an
appropriate quantity for testing from a larger bulk, in such
a way that the proportion and distribution of the factors
being tested are the same in both the whole (lot) and the
part removed (sample).

This has proven very difficult to do with a sampling spear

Sampling –Best Practice

Ideally multiple samples at random intervals should be take from transfer
point with a “pelican” style sampler that transverses the entire cross
section of the stream and will not overflow during sampling, samples
should be taken from an established stream (at least 12” from
discharge)- samples should then be combined and reduced to an
appropriate amount for testing.
These principles are widely acknowledged in metallurgical, agricultural
and grain industry –
Granted we are not dealing with grain but the same concerns and issues
regarding segregation and representative sampling are very much the
same
•  Inspecting Grain--Practical Procedures for Grain Handlers, MP-34. Federal Grain Inspection Service, United
States Department of Agriculture, P.O. Box 96454, Washington, DC 20090-6454. 1991
•  Grain Sampling, Book I. Federal Grain Inspection Service, United States Department of Agriculture, Washington, DC
20250. 1989

AFS Discrepancies

At the Hevi-Sand plant during transfer of our blends to our 25 ton holding tanks
for bagging a automatic sampler is used to sample the entire stream at regular
intervals during filling -every minute-averaging more than 1 sample per ton
these subsamples are combined and sent to the lab for testing

Whole Batch Study

•  Lots are given to our Hevi-Sand
–  Lots are no larger than 25 tons due to the
capacity of the holding bins the material is
blended into
•  An entire batch of typical AFS Red
grade production was investigated at
the plant to look at these issues

Whole Batch Study

23 bags were produced, the measurement from the auto sampler
was 47.28 and this is the value that would appear on Certificate
of Analysis (COA)
•  22 of the bags were tested as below - 1 bag used for “whole bag splitting”
- individual AFS on each bag taken via sample spear
taken from the top of the bag ( Manual)
- A composite sample of the individual spear samples
taken from the top of the bag (Composite Manual)
- 6 individual directional “side spear” samples on each
bag to look for evidence of stratification in the bag
(side spear)
- 6 interval samples from the flow resulting from the
discharging of the contents of the bag
(flow sample)

Whole Bag Splitting

One bag produced was tested via “Whole Bag Splitting”

The entire 1 ton bag was split and reduced down to the sample
size needed for AFS

Value on COA = 47.28
Value from Whole Bag splitting =49.79

Average value from samples obtained from sampling spear in top
of bag
AFS 43.91
Value for Composited Manual Samples= 45.65

Whole Batch Study- Summary of Results

Sampling Method Average Grain Fineness
Value
Composited Top Spear Samples 45.68

Manual Top Spear Samples 43.91

Whole Bag Splitting/Reduction 49.79

Average of All Side Spear Samples 49.09

Average of all Discharge Flow cuts 47.46

Side Spear Sampling

Average of Side Spear Samples

Sample Average Values across Bags in
Batch
Side Spear 1 47.90
Side Spear 2 49.05
Side Spear 3 49.77
Side Spear 4 49.31
Side Spear 5 49.48
Side Spear 6 47.17
Manual top Spear 43.91
COA Value 47.28

Discharge Flow Sampling

Average of Discharge Flow Samples

Sample Average Across All bags

Flow Cut 1 48.25
Flow Cut 2 47.84
Flow Cut 3 47.72
Flow Cut 4 47.34
Flow Cut 5 46.83
Flow Cut 6 46.76
Manual top Spear 43.94
COA Value 47.28

Conclusions

•  The top spear “manual” sample shows the largest
amount of variation and is systematically lower than
samples taken from the same material when flowing
as seen in the COA value and discharge stream
samples
•  Whole Bag splitting also gives an AFS value that is
close to the value reported on the COA
•  Only individual spear samplings yield consistently low
AFS values
•  We are confident that the sizing on the COA reflects
the contents of the bag

Conclusions

•  Segregation is difficult to combat
-anti segregation equipment reduces segregation
by re-blending the material during transfer
-Each time material is transferred there is a
chance for segregation to occur
•  Sampling from the top of the bag even with a spear
yields coarse AFS results

•  A potentially better way would be to sample the
moving material during bag breaking,
–  sampling flowing material is a more preferable sampling
method

We Installed a New Conventional Blender

Conclusions Large Tramp Silicate Particles

•  While we met our internal Silicate level
Specification > 0.8%. Visually we saw
large silicate particles.
•  These particles were very difficult to
remove due to their size and sometimes
their semi-magnetic properties.
•  This made it difficult for the electro-
magnet separation equipment to
differentiate them from small chrome
particles

Conclusions Large Tramp Silicate Particles

Competitor Material

Competition material from UK

Similar array of
small silicates

Looks similar to
February
production under
microscope

25 x

Conclusions Removal of Tramp Silicate Particles by AST’s

Variable binder performance and ADV

•  Problems -:

•  While we were achieving our target ADV values ie
>5ml at Ph3, we had inconsistent set times or low
strengths with Furan resin.

•  Increased acid wash did not resolve the problem

•  Neither did the undesirable increase in catalyst.

Variable binder performance and ADV

•  Problems -:

•  We did not understand the data

•  We did not understand the binders
susceptibilities sufficiently

•  We needed to investigate what we needed to
investigate

Investigation of Resin systems and Hevi-Sand
Main resin systems used with Chromite:

•  Thermal setting
–  Shell process
•  Cold setting
–  Sodium silicate/ Ester
–  Phenolic acid cured or Phenolic no-bake
–  Phenolic alkaline/ ester (Alphaset)
–  furan binders or furan no-bake
–  PU = Phenolic Urethane no-bake (liquid amine)
•  Gas setting
–  Phenolic alkaline/ ester (gas phase) (Betaset type)
–  PU = Phenolic Urethane /gas amine cured (cold box type)
–  Silicate/ CO2

117

Resin systems

Resin systems and Hevi-Sand – cold setting

•  Shell sand:
Usage: core or shell moulding
1 thermoplastic formo-phenolic resin
2 hexamine
Setting type: quick setting by heating at about 160°C
Reach the melting point of the resin
Hexamine generates additional formol to start the setting
Resin becomes a thermo setting resin
Hexamine generates ammoniac which accelerates setting

Old and efficient type system – 1,5 to 6 % addition rate
Not really easily affected with sand quality variation because it contains a
large amount of resin and it is a strong reaction.

118

Resin systems


•  Sodium silicate/ Ester
Usage: moulding and cores – large and medium
1- Sodium silicate 2- Esters (various types)
Setting type: progressive and slow setting
by pH reduction + desiccation generating acid salt + Alcohol:
 Acid salt  progressive pH reduction (neutralisation)
 Alcohol  Gel of silicate
Quite old type system – 2,5 % to 3,5 % addition rate
Difficult to regenerate - Quite slow to obtain full setting
Sand Stays on the basic side after curing.
Not really easily affected with sand quality variation because it contains a
large amount of Binder and it is a slow reaction with long bench life

119

Resin systems


•  Phenolic acid cured or Phenolic no-bake
Usage: moulding – large and medium
1-phenolic resin named PF (Phenol-Formol) 2- Acid (catalyser)
Acid types: Mineral (low Organic (more typical with
According recycling) chromite)
resin type Higher Phosphoric PTSA
reactivity Benzene toluene
and reactivity
Lower Sulphuric Benzene xylene sulfonic
reactivity Benzene xylene Toluene sulfonic

Setting type: poly-condensation + exothermic reaction
0,8 % to 1,5 % addition rate - Low reactivity – needs strong acid
High influence: pH and ADV of sand, T°C, Acid dilution.
Can be affected with sand quality variation because it contains a relatively
small amount of resin and it needs a strong acid

120

Resin systems


•  Phenolic alkaline/ ester (Alphaset type)
Usage: moulding and cores – large, medium and small
1- alkaline phenolic resin (very high pH) 2- various organic esters
Resin type: Soda base or Potassium based
Setting type: creation of alkaline salts + Alcohol to neutralise the area.
The resin can then create progressively a gel (polymerisation) and can
reticulate slowly. 1,2 % to 1,8 % addition rate.
Difficult to regenerate completely as it contains mineral residues.
Very slow to obtain full setting through – easy to strip
Sand Stays on the basic side after curing
Some influence: pH and ADV of sand, T°C. Can be only slightly affected
with sand quality variation as it is slow and binder content is quite
high.

121

Resin systems

•  Furan binders or furan no-bake
Usage: moulding and cores – large and medium
1- Furanic resin 2- Acid (catalyser)
Various Furanic resins type: UF FA; PF FA, UF P, UF PF FA to be chosen
depending on N2, price, free formol, reactivity… expected.
Acid types: Mineral (low Organic (more with chromite)
According recycling)
resin type Higher Phosphoric PTSA
and reactivity reactivity Benzene toluene
Lower Sulphuric Benzene xylene sulfonic
reactivity Benzene xylene Toluene sulfonic

Setting type: poly-condensation + exothermic reaction + Water
0,8 % to 1,5 % addition rate - Low to medium reactivity – needs strong acid
High influence: pH and ADV of sand, T°C, Water content: Can be affected with
sand quality variation because it contains a relatively small amount of resin
and it needs a strong acid addition to set at the expected speed.

122

Resin systems

•  PU = Phenolic Urethane no-bake
Usage: moulding and cores – any size.
1-Phenolic resin 2- Poly-isocyanate MDI 3- Liquid amine (pyridine type)
Setting type: poly-addition of part 1 + Part 2 - exothermic reaction
Part 3 is only a catalyser. Total binder 0,7 % to 1,4 % addition.
The reaction generates a “reticulated polyurethane” resin (thermo setting
resin).
Uniform and rapid setting after reaction started. Stripping can be difficult.
Strong maximum strength is obtained rapidly
Very quick setting time compared to bench life (for high productivity).
Curing efficiency can be strongly reduced in case of water content in the
sand.
High influence: pH, ADV or/and alkaline demand of sand Can be affected
with sand quality variation because it contains a very small amount of
resin and the reaction speed and final strength can be reduced if the
sand contains any residual acids.

123

Resin systems

Resin systems and Hevi-Sand – gas setting

•  Phenolic alkaline/ ester (gas phase) (Betaset type)

Similar as Alphaset but using a gas Ester (methyl formiate)
Binder usage: 1,2 % to 1,8 % addition rate.

Some influence: pH and ADV of sand, T°C. Can not be significantly
affected with sand quality variation as binder content is quite high and
as the gas addition is used in excess most of the time.

124

Resin systems

Resin systems and Hevi-Sand – gas setting

•  PU = Phenolic Urethane /gas amine cured (cold box type)
1-Phenolic resin 2- Poly-isocianate MDI 3- gas amine (Pyridine)

Similar as PU-No-bake but using a gas Amine (methyl formiate)
Binder usage: 0,8 % to 1,6 % addition rate.

Very sensitive to water excess!
Could be affected with sand quality variation because it contains a small
amount of resin; however a excess of gas curing can solve a reduced
curing efficiency due for example to any residual acids.

125

Resin systems

Resin systems and Hevi-Sand
•  Classification Organic or Mineral? - Acid or Basic?

Setting area  Acid Basic

Binder type

Organic Phenolic acid cured PU no-bake
Cold setting Furan PU amine cured
Alkyd resin (old types)

Mineral Phenolic alkaline/ Ester
Sodium Silicate/ester
Silicate/CO2

126

Resin systems

•  Foundry Comparison
Summary - experience in France Competition
Amcol Lot66305 Minelco
Production date DECEMBER 2010 MAY 2011
pH 8,22 ?
ADV pH 3 6,2 ?
ADV pH 4 5 ?
ADV pH 5 4,4 ?
Initial curing rate slow not tried
curing rate very slow expected value
strength development Slow/ under expectation
expected value
FURAN 24 H Strength < expectation expected value

curing rate not tried not tried
strength development not tried not tried
PU 24 H Strength not tried not tried
Details
Trial from FMGC Furan Resimax 1014
Bench life
Curing time with normal cata > 30 min - no setting 10 to 15 min
Curing time with quicker cata 15 min
24 H Strength (standard) lower than comp

127

Resin systems

Summary - experience in France Competition
Amcol Lot35101 Aumas Amcol Lot35216
Production date MAY 2011 MAY 2011 AUGUST 2011
pH 7,55 7,91 7,39
ADV pH 3 4,5 3,1 3,8
ADV pH 4 3,6 ? 3
ADV pH 5 3 1,1 2,5
Initial curing rate slow expected value expected value
curing rate slow expected value quick and then slow
strength development Slow/ under expectation
expected value Slow/ under expecta
FURAN 24 H Strength < expectation expected value < expectation

curing rate expected value expected value Slow
strength development expected value expected value Quick
PU 24 H Strength OK but High value OK but < than Amcol expectation
<
Details
Trial from Manoir Furan HA 21R12 Furan HA 21R12 Furan HA 21R12
Bench life 6 min 5 min 5 min
Remark starts quick & then slow
Curing time 60 min 25 min 60 min
24 H Strength (dog bone) 6,25 6,5 6,2

Trial from Manoir PU? from ASK PU? from ASK PU? from ASK
Bench life not tested not tested not tested
Curing time 21 Min About 25 min 41 Min

128

Resin systems

Laboratory trials Industrial trial November 2011
Summary - experience in France big bag 51859 Competition Competition
Amcol Lot35101 Amcol Lot35216 Plump - Thyssen Amcol 35136 Plump - Thyssen
Production date MAY 2011 AUGUST 2011 AUGUST 2011 JUNE 2011 SEPTEMBER 2012
pH 7,55 7,23 ? 7,51 ?
ADV pH 3 4,5 3,08 ? 4,6 ?
ADV pH 4 3,6 3 ? 3,7 ?
ADV pH 5 3 1,97 ? 3,1 ?
Initial curing rate Not tried Not tried Not tried Not tried Not tried
curing rate Not tried Not tried Not tried Not tried Not tried
strength development Not tried Not tried Not tried Not tried Not tried
FURAN 24 H Strength Not tried Not tried Not tried Not tried Not tried

curing rate expected value very slow expected value Slow expected value
strength development expected value Quick expected value Slow expected value
PU 24 H Strength OK but High value expectation
< expected value < expectation expected value
Details
Trial HA for Magotteaux Lab trial with PU 34201/172 From HAF 24 T trial with PU 34201/172 From HAF
Bench life 23 min 41 min 17 min 22 min 12 min
Curing time 33 min 50 min 25 min > 50 min! 21 min
1 H Strength (standard) 8 18
24 H Strength (standard) 36 24 about 28 35 44

129

Resin systems

•  What happens if the sand is too basic?
Bench life Final strength

Shell sand NA NA

Sodium silicate / ester

Phenolic acid cured
Furan binders
PU no-bake
PU gas amine cured
Phenolic alkaline/ester
(liquid or gas Ester)

130

Resin systems

•  What happens if the sand is too acid?
Bench life Final strength

Shell sand NA NA

Sodium silicate / ester

Phenolic acid cured
Furan binders
PU no-bake
PU gas amine cured
Phenolic alkaline/ester
(liquid or gas Ester)

131

Resin systems

Conclusions Resin systems and Hevi-Sand
•  Discussion about pH, Acid demand and Alkaline demand?

–  The most important for our customers is to receive a consistent
and acceptable quality that optimizes the defined binder process.

–  Trying to tune the process with more acid washing risks damaging
actual results obtained with PU or Furan, ie improving Furan
performance may impair PU performance. Better grain cleanliness
seems to be the best way forward.

–  Competition sand does not always have a low pH but ADV at pH5 is
can be lower: that means that we may have a buffer (like sponges)
on/ in our sand which is activated “post ADV” during curing. If we
over acidify the sand, it treats the problem temporarily. We do not
know all the chemical reactions…but again cleanliness is key.

132

Resin systems

Conclusions Resin systems and Hevi-Sand
•  Discussion about pH, Acid demand and Alkaline demand?

–  The September sand has we over acidified, for Furan, it accelerated
the reaction initially because of this available acid. In the second
phase after the acid had been neutralized, the reaction continues at
a normal speed, as with the normal May sand, but still slower than
with competition chromite.

–  This over acidification is probably just a temporary booster but the
reduced test values, compared to competition, does reoccur.

–  For PU, the over acidified sand remaining has a negative impact
and artificially extends the bench life and stripping time. It appears
that it damages the poly-addition process of PU., as the final
strength is reduced.

133

Resin systems

•  Discussion about pH, Acid demand and Alkaline demand:

What kind of pollution should we look for in our sand?
–  Dust increasing binder and catalyser need
–  “Salts” with acid tendency
–  “Salts” with basic tendency
–  “Amphotère”? (basic & acid substances)
•  Double function to generate acid or basic effects depending on
the condition!!
•  What should we measure and control?
–  pH (really not sufficient)
–  ADV (not enough as we may have “double function substances”)
–  Also “Alkaline demand” as it should balance the ADV
–  Various resin systems “bench life” and “strength”

134

Resin systems

•  Conclusion
Our experience shows that 2 resin systems can really be affected with
HEVI-SAND quality variation:
1) FURAN system
2) PolyUrethane (PU) systems cured with liquid amine.
Different reasons can explain it:
a) low addition of binders for these kind of process (especially true for PU)
increases weaknesses of our sand (pollution, salts, fines, …)
b) pH, acid demand or alkaline demand play a large role in the setting process
(speed and final strength) of this type of binders.
- "Acid area" setting for FURAN
- "Basic area" setting for PU
We can conclude that performance improvement for these systems should
result in improvements for any other system.
It is a priority to test resin performance of Hevi-Sand as a control
parameter
135

Resin systems

Improved Turbidity= Improved Hevi-Sand

•  In our Hevi-Sand, Binder Strength and Turbidity have strong
relationship
–  In our case, the turbidity is associated with insufficient removal of clay like
material on the grains resulting in slow set times and lower 24 hour tensile
strengths
–  Acid Demand value not as a direct relationship as previously thought
•  can be influenced by claylike material giving elevated ADVs but this can also “hold “
onto residual acid from washing and give low ADV values but poor binder performance
(especially in PUNB)

•  Relationship not as evident in competition likely because of nature
of particles causing turbidity.
–  More inactive fines with less clay / buffer like material?
–  With competition material, we have seen some low turbidity, some high turbidity
and various acid demand values, but usually reasonable binder performance

Extended Turbidity Testing

•  Typical turbidity tests didn’t always give us the
whole picture as extended mixing always results in
higher values
•  After plant upgrades, both regular test and
extended mixing/washing turbidity values (cake
mixer test) were reduced significantly
•  Double washing since October has been
continuously improving turbidity,
•  The recent wet plant upgrades and double washing
are resulting in very good turbidity values currently.

Comparison of End Products

Sample NTU 24 hour 24 Hour
Furan (psi) PUNB (psi)

R11-0494 July, 2011 single wash 1052 216 109
R12-0037 Jan, 2012 2x wash 387 332 183
R12-0085 Feb, 2012 Production 232 378 270
R11-0568 Competitor ex UK 1048 329 221

Competitor material has high turbidity but good binder properties. It
is possible that their turbidity has more inactive ﬁnes while our is
more clay / buffer-like particles

Extended Turbidity Testing

January, Feb, 2012 Jan, 2012 Feb, 2012
2012 Washed End Product End Product
Washed Feed
Feed (1 pass)
(2
passes)

Original NTU from 147 135 387 232
standard test
1st wash in cake 1762 1041 1918 308
mixer (5 minute mix)
2nd wash 1022 548 1118 306
3rd Wash 603 523 615 246
4th Wash 611 394 577 215

Comparison of classifier underflow samples

Turbidity
-‐
Mul6ple
Washing

2000

1800

1600

1400

Classifer
U/F
pre
upgrade

Turbidity
NTU

1200

1000
Classifer
U/F
aBer

upgrade

800

600

400

200

0

Original
Turbidity
1st
Wash
2nd
Wash
3rd
Wash
4th
Wash

Measurement

Wash
number

r on 2nd pass

Comparison of Finished Product Turbidity

Turbidity-‐Mul6ple
washing

2500

2000

1500

Turbidity-‐
NTU

Jan
end
Product

1000
February
End
Product

500

0

Original
Turbidity
1st
Wash
2nd
Wash
3rd
Wash
4th
Wash

Measurement

Wash

,

SEM and surface area measurements to conﬁrm

Surface Area of Hevi-Sand
Sample BET Kr Surface Area Time frame
( m2/g)

Competitor CS -11-005 0.03 July 2011

Hevi Sand Red 0.98 July 2011
R11-0415

Hevi Sand Red 0.10 Feb 2012
R12-0085

• Big reduction in our Surface area for February production

sphere
sphere
cubic

parIcle
size
50
100
100
micron

S.G.
4.5
4.5
4.5
g/cm^3

surface
area
per
parIcle
7.85E-‐09
3.14E-‐08
6E-‐08
m^2

volume
for
each
parIcle
6.54167E-‐08
5.23333E-‐07
0.000001
cm^3

mass
per
parIcle
2.94375E-‐07
0.000002355
4.5E-‐06
g

number
of
parIcles/g
3397027.601
424628.4501
222222.2

surface
area/g
0.0267
0.0133
0.0133
m^2/g

Comparison End Products
24
hour
Tensile
Strengths

400

350

300

24
hour
strength
-‐psi

250

200

24
hour
Furan
Strength

24
hour
strength
in
PUNB

150

100

50

0

Sep-‐11
Jan-‐12
12-‐Feb
CompeItor

Produc6on
date

Continued Improvement in Furan Performance

Produc6on
Date
Strength
Hour
Tensile
Strength
in
Furan

400
350

350

3x
washed
300

24
Hour
Tensile
Strength
-‐psi

300

Strip

Time
-‐Minutes

250

250

Compe6tor's
Strength/
Strip
6me
200

200

24
hour
Tensile
Strength

150

strip
Ime
(min)

150

100

100

50

50

0
0

Furan Binder Reaction Time vs. Temperature
Time
vs.
Temperature
-‐
1.0%
Furan
Binder

28,5

28

27,5

27

Temperature
C

26,5
Jan-‐12

Feb-‐12

26

25,5

25

24,5

0:00:00
0:14:24
0:28:48
0:43:12
0:57:36
1:12:00
1:26:24
1:40:48

Time

cent production shows a higher peak and higher sustained tempe

Continued Improvement in PUNB Performance

Produc6on
Date
vs.
24
hour
tensile
strength
in
PUNB

300
40

35

250

24
hour
Tensile
Strength-‐
psi

30

Strip

Time
-‐Minutes

200

25

Compe6tor’s
Strength/Strip
6me

150
20

15

100

10

24
hour
tensile

strength

50

Strip
Ime

5

0
0

R11-‐0415
5/11
9/12
9/22
9/24
10/26
Jan-‐12
Feb-‐12
RY

Acid Demand Test with Organic Acid 0.1 N PTSA

Sample pH ADV ADV ADV
@pH3 @ pH 4 @ pH5

R11-0494 single wash 6.74 5.9 3.3 2.8

R12-0037 Jan 2x wash 8.24 6.7 4.9 4

R12-0085 Feb 7.99 7.4 4.1 3.6
Production

R11-0568 competitor ex 7.56 6.5 4.3 3.8
UK

The data doesn’t show a strong tie between ADV and strength even with organic acid

There is deﬁnitely some relation between ADV and performance, as extremely high or low ADV
will likely affect strength, but it does not appear as closely linked as previously thought.

Typical Acid Demand Test with 0.1 N HCL

Sample pH ADV ADV ADV
@pH3 @ pH 4 @ pH5

R11-0494 single wash 6.74 3.4 2.3 1.8
R12-0037 Jan 2x wash 8.24 4.7 3.1 2.7
R12-0085 Feb 7.99 5.4 3 2.5
Production

R11-0568 competitor ex 7.56 3.9 2.2 1.9
UK

Lower pH value for single wash was likely related to higher acid dosing and incomplete rinsing

Pre Wet Plant Upgrade Samples and Data(Jan 2X Washing)

Sample ID Description Turbidity pH Bulk Density
NTU lbs/ft3 ( kg/m3)
R12-0031 1st Wash Attritioner Feed 415 6.87 178 (2859)
R12-0032 1st Wash Attritoner Discharge 374 6.80 179 (2876)
R12-0033 1st Wash Classifier U/F 114 6.62 182 (2920)
R12-0034 2nd Wash – Attritioner Feed 182 6.98 183 (2931)
R12-0035 2nd Wash- Attritioner Discharge 491 7.52 183.5 ( 2939)
R12-0036 2nd Wash – Classifier U/F 147 6.99 183 (2932)
R12-0037 Jan Production from Double 387 8.24 175 ( 2801)
Washing Process

Post Wet Plant Upgrade Samples and Data(Feb 2012)

Sample ID Description Turbidity pH Bulk Density
NTU lbs/ft3 ( kg/m3)
R12-0074 Primary Attritioner Feed 784 7.33 186 (2975)
R12-0075 Primary Attritioner discharge 948 7.49 181 (2903)
R12-0076 Primary Classifier U/F 373 7.22 183.5 (2939)
R12-0077 Secondary Attritioner feed 178 6.88 186 (2979)
R12-0078 Secondary Attritoner discharge 910 6.97 186.5 (2987)
R12-0079 Secondary Classifier U/F 202 7.32 182.5 (2928)
R12-0080 Bunker Cyclone U/F (wet feed) 135 7.26 183.5 (2939)
R12-0085 End Product from Feb 232 7.99 185 (2963)

Process now “double washes” with a single pass through wet plant this data represents the ﬁrst
Pass through the wet plant R12-0085 is End Product

Decreasing Turbidity- Increasing Bulk Density

End
Product
Turbidity
and
Bulk
Density

700
190

600

Compe6tor’s
Turbidity

185

Bulk
Density

Bulk
Density-‐
lbs/N3

500

Turbidity
-‐JTU

180

400

Turbidity
(JTU)

300

175

Bulk
Density
lbs/B3

200

170

100

0
165

Sep-‐11
Jan-‐12
12-‐Feb
CompeItor

Increase in bulk density seen in the

SEM Images Support Lab Data

•  Images taken at McCrone Laboratories in Illinois
•  Images in Backscatter mode
–  lighter colours = heavier elements ,such as Cr, darker colours are
Lighter elements like Si
•  Dark deposits are non-liberated or potentially re-deposited silicate
impurities on the surface of the chromite
•  February process ( after installation of new equipment)
-Appears to be more efficient at deliberating silicates from
chromite grains
•  February classifier images are after each classifier on the 1st pass
through wet plant
•  Shows good cleaning after single pass through wet plant
•  good baseline for comparison to material after dewatering screen
•  Currently all material will still receive a second trip through wet
plant for maximum cleanliness of end products

Cleaner Surfaces-SEM Images
2x Wash - January

Single Wash

•  Continued improvement
in End Product turbidity
seen on SEM of End
Products as well
•  Upgrades giving us
Plant upgrade Feb 2012

cleaner surfaces than
January double wash

Same Spots – Fewer of Them

January End February End Product

Product

•  The surface deposits have a
competitor

similar composition

•  Competition still shows some

deposits as well

February 2012 -Single pass through Wet Plant
February Classifier Underflow After 1st UCC

February Classifier Underflow After 2nd UCC

End Products
January End Product

February End Product

Summary

•  Increased Attritioning / washing
showed-:
–  Improved performance (strip time, strengths)
which are closely tied to turbidity/ grain
cleanliness

•  Use of AST’s in the dry process-:
- have significanly reduced large silicate particles

•  Bulk Density increasing
–  more fines but hard to see in AFS test due to
sampling difficulty, but clearly reduced turbidity
increases flowability and tapped bulk density.

Summary

The research and resultant $5m plant up-
grade has allowed production of
ULTRA GRADE Hevi-Sand®.
Q3 2012 will see another step as the de-
watering screen and further AST units,
cement consistencey into the product.

What we believed and now can demonstrate to be true

•  We believe we now understand more
than any company in the field of the
impact residuals have on the
performance of chromite in foundries.
•  We believe the current acceptance
standards and test procedures in
foundries should change if they need to
optimize as cast casting quality through
the use of chromite sands

Hevi-Sand® what foundries order
Typical foundry chromite order speciﬁcations

FeO%

SiO2%

CaO%

Turbidity

AFS

ﬁnes

LOI

PH

Acid demand,

Cr%

ph 3, ph4, ph5

>46%

<29%

<1%

<0.5%

<250ppm

NA

<1%

NA

<8.5

10ml, 6ml 4ml

>45%

<29%

<1%

<0.5%

NA

50 <5%

NA

NA

NA

>44%

<25%

<4%

NA NA

42 NA

NA

NA

NA

>44%

<29%

<4%

<1.0%

<400ppm

50 NA

0.5%

NA

NA

>46%

<25%

<0.6%

<0.4%

<150ppm

48-52

<1%

0.1%

<8.0

8ml 4.5ml 2.5ml

>46%

<26%

<0.6%

<0.4%

<250ppm

60-70

<1%

0.1%

<8.0

8ml 4.5ml 2.5ml

Hevi-Sand® what foundries order

Typical foundry chromite order speciﬁcations

•  These specifications are often historic and based on
availability rather than desire

•  Foundries have often combined or adjusted specifications
in an attempt to solve consistency problems

•  Foundries have shorthanded there specifications by not
specifying what test procedures should be used

Foundry orders / Testing

•  Foundries typically test-:

•  Chemical analysis, Afs, fines, Ph, Adv, turbidity, LOI.

•  They rarely specify any sampling method or test procedure

•  The major customer hurdles we have encountered so far
which have impacted the project, are order specs which do
not reflect what they actually want to receive and testing /
test methods which are not standard to the industry.
•  We have also had specification requests for material which
is not available from any supplier, which foundries have
been purchasing for years effectively out of spec.

Hevi-Sand® TESTING

•  CHEMICAL ANALYSIS

•  What most current suppliers define as foundry: +46%Cr, -29% Fe,
-1%silica. Was prior to Hevi-Sand the highest quality material
available.

•  Most people are testing on expensive XRF equipment which one
would think would produce very good consistent results, the
reality is that sample preparation and calibration coupled with
correction criteria can produce very different results on the same
sample

Hevi-Sand® TESTING

•  CHEMICAL ANALYSIS reported at 46.45%Cr same sample
differing grinds
Amount retained (g)
Screen Size Mesh #1 #2 #3 #4 #5 #6
106 µm No.140 7.32 6.4 4.59 2.69 2.69 1.73
75 µm No.200 1 1.44 1.33 1.4 2 1.76
53 µm No. 270 0.52 0.84 0.85 0.99 1.39 1.53
45 µm No. 325 0.25 0.5 0.52 0.58 0.82 1.05
20 µm No. 635 0.57 1.04 1.14 1.58 2.52 3.41
Pan Pan 0.48 1.11 1.01 1.06 1.53 1.06
total 10.14 11.33 9.44 8.3 10.95 10.54
% passing 200 mesh 17.95 30.80 37.29 50.72 57.17 66.89
XRF Data %
Cr2O3 42.988 40.438 41.495 42.663 44.707 45.07
SiO2 0.958 1.913 1.493 1.325 0.572 0.626
FeO 23.748 22.264 22.778 23.538 24.753 24.964
MgO 9.618 9.983 9.556 9.718 9.83 9.895
Al2O3 12.841 12.793 13.408 13.313 14.132 14.341
CaO 0.111 0.111 0.105 0.101 0.092 0.092
Sum 90.264 87.502 88.835 90.658 94.086 94.988

Hevi-Sand® TESTING

•  AFS Number: foundry grade typically 45-55afs
•  The major issues regarding this analysis are use of appropriate sieves
(ASTM sieves vs.. British Standards vs.. ISO sieves)
•  Grain Fineness is calculation that is intended to be made from
designated series of ASTM sieves (6,12,20,30,40,50,70,100,140,200,270
and pan)
•  Percentage retained on each sieve is calculated and multiplied times a
set factor for each sieve
•  Grain Fineness # = Total (after multiplied respective factor)/ amount
collected in the sieve analysis ( usually close to 100 grams or
normalized to 100 grams)
•  British Standard sieves have a different sieve aperture for a give sieve
#; example ASTM 30 mesh = 600 micron; British Standard 30 mesh =
500 micron
•  These differences in sieve size can yield different AFS numbers for the
same sand if calculated from ASTM vs. British Sieves

Hevi-Sand® TESTING

•  AFS Number same sample different sieves
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Hevi-Sand® TESTING

•  AFS Number
•  Because of the factors in the Grain Fineness
calculation one can arrive at different results on
the same sample

•  Therefore it is misleading unless other
parameters are specified (i.e. % passing 140
screen, or 80% between 425 and 212 micron etc.)
Fines are usually specified because of
experiences with fine impurities
•  WHAT YOU SEE IS NOT NECESSARILY WHAT
YOU GET

Hevi-Sand® TESTING

•  Acid demand and PH

•  These tests are important since variations can
cause problems with acid catalysed binder
systems, resulting in loss of properties

•  Acid Demand testing involves adding a known
amount of acid to a sample, agitating and letting
the sample sit for 1 hour, then titrating with a
base to pH 3, 4, and 5 to determine the amount of
acid consumed to reach each pH level

Hevi-Sand® TESTING

•  Acid Demand and PH

•  Typical specifications are 10, 7 and 4 ml for pH 3,
4 and 5 respectively
•  Even if in spec large variations in ADV are
undesirable
•  pH generally should be close to neutral (pH=7)
less basic sands generally will have a higher Acid
Demand as well

Hevi-Sand® TESTING

•  Acid Demand and PH

•  What we found in the earlier work shown was that
ADV and Ph depend on grain cleanliness,
otherwise acid masking can occur which
achieves the correct specification requirements
but in practice leads to significant problems with
binder systems

•  What you see is not necessarily what you
get

Hevi-Sand® TESTING

•  LOI

•  Typically there should be no loss on ignition
associated with quality chromite sand if the test
is performed in a reducing atmosphere such as
Nitrogen
•  In the presence of air, the iron oxide transforms
and increases in weight
•  LOI Test should be carried out in oven with N2
atmosphere or similar.

Hevi-Sand® TESTING

•  LOI

•  The aim of this test is to look for contamination/
impurities that could impact lower the melting/
fusion point of the chrome, or impact other
thermal properties

•  It is included in many QA specification but most
companies cannot test it

Hevi-Sand® TESTING

•  LOI
Fig 19b: TGA in air (oxidizing environment)

Fig 19a: TGA analysis in Nitrogen Environment

Hevi-Sand® TESTING

•  TURBIDITY

•  A lot of discussion surrounding this test; what do
the results mean, how it should be tested
•  Turbidity is a measure of light scatter caused by
suspended solids in a liquid sample.
•  Turbidity in Chromite, is generally attributed to
low melting point accessory silicate mineral
phases
•  High turbidity is thought to contribute to certain
types of foundry defects such as double skin, and
in can contribute to higher SiO2 levels

Hevi-Sand® TESTING

•  TURBIDITY

•  Jackson Turbidity test has been the industry
standard, measured in ppm of silica or Jackson
Turbidity Units (JTU) this test compares the
visual turbidity of a sample to a reference sample
of known ppm silica

•  Measures the scattering of light by the amount of
time required to obscure a standard candle flame
under the testing cylinder

Hevi-Sand® TESTING

•  TURBIDITY

•  Drawbacks with Jackson method include
variability of calibration curves, standards and
operators
•  Each tube is supposed to be custom calibrated
by users based on solutions prepared from
diatomaceous earth
•  Candle light flame as a light source has
limitations in examining low turbidity samples,
samples with very fine suspended solids and
samples with color or bright surroundings.

Hevi-Sand® TESTING

•  Modern instrument (Nephelometer) makes use of
fixed angle light source, at a fixed wavelength
and modern Formazin based standards to
determine turbidity, typically specified in most
other turbidity testing applications (waste water,
brewing etc)

•  Formazin Standards are traceable, certified and
reproducible, not all turbidity standards are true
Formazin, but all are traceable to Formazin
reference standards

Hevi-Sand® TESTING

•  Modern Nephelometers report in a variety of
interchangeable units all related to Formazin
Standards the most common being NTU, FTU or
FAU,
•  NTU and JTU or ppm are not equivalent and there
is no consensus on correlation or conversion
factors (typically JTU x 2)
•  Not all Turbidity meters (Nephelometers) are the
same, many only employ a single 90 degree
detector for analyzing turbidity, this works well
for low turbidity samples like drinking water, but
may require dilution for higher turbidity samples,
most portable turbidity meters are of this variety

Hevi-Sand® TESTING

•  Other turbidity meters employ
additional detectors to extend the
calibration range and overcome color
effects in the sample
•  These type of meters appear to be
most suitable for analyzing chromite
sands
•  Amcol uses this type of turbidity
meter

Hevi-Sand® TESTING

Turbidity Meters

Hevi-Sand® TESTING

•  Every method requires agitation and
traditionally this is done by shaking
sample by hand in sealed jar or beaker
•  Variation in results observed depending
on how long and by whom the sample was
Shaken
•  12 different individuals were asked to
perform the test, using the same
equipment and method, high was 739 NTU,
low was 378 NTU

Hevi-Sand® TESTING

•  The variability demonstrated a need to
standardize the shaking process
•  Several things were tried, shaking table, magnetic
stir bar/ stir plate, rotation/ tumbling, wrist action
shaker
•  It was observed during this testing that increased
agitation time yielded higher turbidity values,
values still increasing at 30 minutes of agitation
•  This brings up the issue of are we concerned
about total turbidity or only what can be
generated in short amount of time?
•  What is more realistic in a foundry setting?

Hevi-Sand® TESTING
•  From a testing perspective it is unreasonable to
have a 30 minute test, so 1 minute agitation was
chosen using the wrist action shaker because the
results were thought to reasonable compared to
shaking method and the reproducibility
•  The 12 individuals were asked to repeat the test
with the wrist action shaker
•  Low result was 434 NTU and the high was 512, a
much closer grouping of results
•  A new proposed method includes the use of the
Hach 2100 N turbidity meter and the wrist
action shaker
•  A complete procedure and data regarding this
turbidity testing appears in our HS tech paper

Hevi-Sand® TESTING
•  Where we are now.

•  Completing a tech paper which reappraises foundry
sand testing procedures and acceptance
specifications.
•  We believe the industries institutes should evaluate
these findings and try to standardize there
recommendations.

Ultra Grade Hevi-Sand®
•  Where we are now.

Hevi-Sand® What it means for your Foundry

To Maximize foundry performance

We must understand what foundry problems are and
there likely causes

•  .


Our Product Strategy

To Allow foundries to make castings like these
consistently

.

Poor Quality What it means for your Foundry

Our Product Strategy

Help avoid making castings like these.

.

Double skin defects

•  High impurity levels
•  High acid demand
•  High fines
•  High binder levels
•  Long pouring times
•  High pouring
temperatures.

Double skin defects
•  Click icon for Double Skin Information
Document

•  But also check Silicates content of chromite
•  Is your mixer feed hopper clean or full of low
melting point magnesium silicate dust
•  Are you adding excess resin and catalyst to
compensate for variable sand quality
•  Do you have a segregation problem.
•  Do you have a thick enough, consistent thickness
layer of chromite.

Other defects BURN IN / FUSION

•  .

Other defects Poor Surface Finish / Overheating

•  .

Defect Poor Surface Finish / Overheating / Fusion
•  What’s in your sand, is it thick enough.

•  Are you moulding correctly.
•  .

•  christmas tree effect.

•  Veins

Hevi-sand® Technical FoundrySolutions
•  Large reduction in low melting point silicates,
(increased fusion temperature, improved heat abstraction)
•  Improved grain cleanliness, (less dust generation in
feed hoppers, improved performance binder stability)
•  .
•  ADV / PH controlled in-line against foundry resins
not data sheets ( reduced additions of resin + Catalyst
more predictable set and strip times, less gas generation)
•  Sized to your casting requirements, (permeability
and packing density control)
•  Segregation control, (in-line testing ensures what’s on
the bag is in the bag)
•  A global team of Foundry Trained Sales
Engineers to visit your Foundry

Hevi-Sand® Benefits
•  Your Foundry Benefits
•  Global Consistent brand “Hevi-Sand®”
•  Unique value of “Mine to Customer”, “Face to Face”
•  Ultra grade tailor made product “Hevi-sand®”
•  Onsite technical advise, service and support
•  Continuity of supply with local stocking points.
•  Price stability.
•  Interactive website, plant visits
•  A large in house lab and research facility at your
service

Hevi-Sand® other Markets

•  Nozzle Sand or Well Filler

Sliding Gate Design

1 A well block is
incorporated into the
ladle lining above the 2 Before the steel is
sliding gate tapped into the ladle the
well is filled with
refractory sand to
protect the sliding plate
α

Well block

Sliding plate

3 When the slide is opened the
filler material should flow out
allowing the steel to pass through
the nozzle

Well filler performance
1% change in opening can save a plant
120,000tons of steel a year

Depends on : Penetration/interaction of steel
• chemistry filler
• chemistry steel Infiltration of slag Depends on :
• Steel pressure • cleaning of ladle
• Pore size distribution of filler • cleaning of nozzle/well block
• Amount of sintering filler • quality of well block
• time/temp heating facilities
• viscosity of slag
Sintered layer
α
Well filler

Thickness & strength
Depends on :
• chemistry filler
Well block homogeneity
Depends on :
• chemistry steel • flow ability
• time • water content
• temperature • grain size distribution
• grain size distribution • segregation
Sliding plate
Depends on :sintered layer/ steel penetration/well filer/slag infiltration
Opening rate diameter of nozzleshape of well block quality of the filling of the well block = α

Hevi-Sand®

•  It has been stressful and caused
premature hair loss for some.

Hevi-Sand®

•  It has been even more stressful for others.

Hevi-Sand®

•  But not for everyone.

Ultimate hevi sand

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