Client List Highlights
CLIENT
SAMANCOR MANGANESE DIVISION
PERIOD
1989-1990
MANAGER
Mr. D Wellbeloved
Manganese Alloy Development Manager
DESCRIPTION
Pre-tax cash flow maximization of the total Mn Division
of Samancor:
• Mines
• Dense media separation
• Sinter plant
• Furnaces
• Alloy sales
USER'S
DECLARED BENEFIT
The LP-Model used as a Decision Support System has
indeed the potential to supply sufficiently detailed information to support
complex decisions and the financial benefits which can result from these better
decisions outweigh, by far, the cost of the system. The use of the system can
become more sophisticated and sensitivities can be performed to show the effect
of possible future changes on business.
MODEL
SIZE
+-2500 Unknowns in 2000 equations
+-200 Integer unknowns
CLIENT
ISCOR COAL DIVISION
PERIOD
1991
MANAGER
Mr. J van der Merwe Grimes
Head: Coal Division
DESCRIPTION
A group coking coal procurement study was conducted and
included transport optimisation for routes, mining cost curves and delivered costs
of local and foreign suppliers. The use of an existing coke quality production
model was incorporated. Proposed coking coal blends were subjected to field
tests.
USER'S
DECLARED BENEFIT
Coking coal blends were changed and import volumes were
re-arranged from off-shore sources as well as volumes from our own source and
local outside suppliers. It is believed that total procurement cost could be
reduced by between 5% and 10%.
MODEL
SIZE
+-200 Unknowns in 170 equations
+-20 Integer unknowns
CLIENT
ZIMBABWE ALLOYS
PERIOD
1991-1992
MANAGER
Mr. R Petzer
General Manager
DESCRIPTION
The entire ferrochrome operation was modelled: mining
reserves, mining cost curves, stockpiles, washing, transportation, briquetting,
blending, smelting in submerged arc furnaces (taking slag chemistry, heat
balances and metallurgy into account) as well as the sales volumes, product
specifications, exchange rates and selling prices.
USER'S
DECLARED BENEFIT
Linear programming has enabled studies to be undertaken
to maximize corporate profits, new thought has been provoked and new ideas
propagated to facilitate the achievement of desired goals.
MODEL
SIZE
+-1000 Unknowns in 700 equations
+-200 Integer unknowns
CLIENT
DE BEERS (MARINE)
PERIOD
1993-1994
MANAGER
Mr. Andreas von Johannides
Senior Ore Evaluation Engineer
DESCRIPTION
Minimization of diamond grade left behind in the sea
bed during mining of the ore body under constraints of various mining vessel
capacities, resource availability and grade distributions.
USER'S
DECLARED BENEFIT
Confidential
MODEL
SIZE
+-400 000 Unknowns in 400 000 equations
+-350 000 Integer unknowns
CLIENT
CARGO CARRIERS
PERIOD
1993-1995
MANAGER
Mr. T Ramage
Company Secretary
DESCRIPTION
Optimisation of the entire Steel Division fleet from a
vehicle utilisation point of view. Overnight shunting was permitted in order to
minimise the number of truck/tractors working day and night shifts, thereby
releasing as many vehicles as possible for outside assignments.
USER'S
DECLARED BENEFIT
Based on model results, an overnight shunting operation
was implemented, thereby causing an almost doubling of the productivity of the
participating truck/tractors.
MODEL
SIZE
+-9 000 Unknowns in 4 000 equations
No integers
CLIENT
GOLD MINES
PERIOD
1991-Present
MANAGER
Varying
DESCRIPTION
Cash flow before tax maximisation of a deep level mine's
operation under constraints of :-
• Ore reserves (immediately available
and in situ)
• Gold grade per zone
• Underground transportation network
• Mill, plant and shaft capacities
• Opening up/development/stoping
predecessor time-lag
• Labour force availability and
productivity factors
USER'S
DECLARED BENEFIT
Project work conducted resulted in typical benefits
e.g. the journal of the SAIMM (May 1978) reports a 9% average increase in stoping production on a gold
mine, as a result of implementation of LP-model results.
MODEL
SIZE
+-9 660 Unknowns in 12 186 equations
+-3883 Integer unknowns
CLIENT
ZIMBABWE MINING AND SMELTING COMPANY (PVT) LTD
(ZIMASCO)
PERIOD
1995-1996
MANAGER
Mr. S Jena
General Manager
DESCRIPTION
Pre-tax net present value (NPV) maximisation of the ferrochrome
operation at the Kwekwe plant, entailing mining, washing, ore transportation,
agglomeration, smelting (metallurgical balances, slag chemistry and heat
balance), alloy cleaning and sales. The model is a multitime period model.
USER'S
DECLARED BENEFIT
The evaluation of effect on unit cost of production and
quality af alloy, through introduction of changes in raw materials, have been
made easier and considerably faster. The frequent application of the model has
encouraged improved operations in terms of increased cost effective alternative
ways of operating the plant.
MODEL
SIZE
+-25 000 Unknowns in 16 990 equations
+-10 Integer unknowns
CLIENT
ANGLO AMERICAN CORPORATION OF SOUTH AFRICA
New Mining Business Division
PERIOD
1997-1998
MANAGER
Mr. A Ramsay
Consulting Metallurgist
DESCRIPTION
The nickel/copper mining, ore concentration, smelting,
matte refining and selling activities of A.A.C. and related producers were
modelled as a mixed integer program with a view to finding the most profitable
long term strategy (15 years) for the group from an N.P.V. point of view.
USER'S
DECLARED BENEFIT
Model results indicated clear strategies resulting in
the more than doubling of the group NPV compared to the existing planning.
Worth-while Southern African opportunities for pooling Ni/Cu resources,
including the shutting down of production units and the expansion of others,
were identified and after presentations to the Boards of the companies as well
as to committees of some of the regional Governments, the strategic planning of
the companies were adjusted accordingly.
MODEL
SIZE
+-8 475 Unknowns in 9 653 equations
+-1170 Integer unknowns
CLIENT
SINAI MANGANESE COMPANY in EGYPT (ABU ZENIMA)
PERIOD
1998
MANAGER
Mr. Allie El-Din Badra
Chairman
DESCRIPTION
A cash flow maximising stand-alone ferro-manganese furnace
linear programming model. Includes metallurgical and slag-chemistry constraints as well as
an energy balance. Model is used for planning the blending of raw materials - manganese
ores from all over the world as well as reductants and fluxes. All plans to ensure that final
salable alloy is within specification.
USER'S
DECLARED BENEFIT
The stand-alone ferro-manganese furnace linear programming model is
now performing in a very good way. We (the Plant Management and me), are very impressed
concerning what was done during the visit of your two gentlemen to the plant.
MODEL
SIZE
+-50 Unknowns in 40 equations
No integer unknowns
CLIENT
De Beers Consolidated Mines : Kimberley Mines
PERIOD
2004-2007
MANAGER
Corneel (J.C.) du Toit
Mine Planner : Kimberley Mines
DESCRIPTION
The objective function of the model is to maximise the total Net Present Value of Kimberley Mines.
The model can also be used to maximise the total carats produced by Kimberley Mines.
USER'S
DECLARED BENEFIT
The results of the project indicated that the old spreadsheet based Mine Plan was not
practical since it violated two mass balance constraints within the Combined Treatment Plant. The newly developed
system was used to generate a mining schedule that did not violate any constraints while still delivering the
same Net Present Value and overall throughput (Scenario 2). The system also illustrated that the plant could
improve the annual throughput with 18.2% and increase the NPV and the total carats recovered with 8.4% and 9.7%
respectively by changing one screen size in the plant (Scenario 3). In summary: The newly developed system can
generate an optimal, practical mine plan in less than a tenth of the time required for the old spreadsheet based
model. The new system can also do various what-if scenarios that the previous model could not answer.
MODEL
SIZE
+-5 600 Unknowns in +-6 300 constraints for a ten year plan
704 Integer Unknowns