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.

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MODEL SIZE
+-5 600 Unknowns in +-6 300 constraints for a ten year plan
704 Integer Unknowns

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