Cato Ridge Works
In order to beneficiate the manganese ore from their mines in the Northern Cape, Assmang established Cato Ridge Works (formerly Feralloys Limited) in 1956 and construction was started on a ferro manganese smelter at Cato Ridge approximately 60km from Durban in KwaZulu-Natal. The first alloy from this plant was exported in 1959.
Ferro Manganese Production Process
The Works currently operates 4 submerged arc furnaces which are controlled by PLC based supervisory systems; In addition, a Metal Recovery Plant from slag is also in operation. The plant currently has a hot metal capacity of +/- 195000 tons per annum.
The furnace raw materials are delivered by rail and off-loaded using wagon tipplers and transported to the raw material bays by conveyor belts. Manganese ore is railed from the Nchwaning and Gloria mines in the Northern Cape. Some third party ores are used as “sweeteners”.
Reductants in the form of metallurgical coke and anthracite peas are procured locally and internationally and in conjunction with the Soderberg continuously baking electrodes form the source of carbon units required for the smelting reaction. All raw materials supplied are monitored closely for phosphorous. (Map)
Cato Ridge Alloys
Cato Ridge Alloys (Pty) Ltd is a joint venture between Assmang, which holds a 50% interest, Mizushima Ferroalloys Company Limited, which holds a 40% interest and Sumitomo Corporation which holds 10%. The Company was formed during 1996 for the production of refined ferro manganese utilizing high carbon ferro manganese from the Cato Ridge Works as the feedstock. The construction of the plant started in 1997 and the first refined ferro manganese for export was produced at the beginning of 1998.
Production of Refined Ferro Manganese
Production of refined ferro manganese is carried out in a top blown bottom stirred converter by preferential oxidation of carbon. Mizushima Ferroalloys of Japan supplied the technology. The plant currently has a capacity to produce up to 60,000 tons of refined ferro manganese per annum. (Map)
In 2010 Assmang’s conversion of some of the furnaces at Machadodorp Works from charge chrome to ferro manganese started. In July 2010 Furnace 5 was successfully converted to high carbon ferro manganese. The first manganese alloy from this furnace was exported in October of the same year. Since then a further two furnaces were successfully converted. The Works is currently only operating one furnace on high carbon ferro manganese. The one charge chrome furnace has been idle since 2012, however production of fines and chips continues. (Map)
Assmang Limited have a 54.36% shareholding in an offshore Ferroalloys project in Sarawak, Malaysia called Sakura Ferroalloys Sdn. Bhd. There are two other shareholders in this project, Sumitomo Corporation (26.64%) and China Steel Corporation (19%).
The smelter was commissioned in 2016 and will have an annual capacity of 170,000mt per annum, producing High Carbon Ferro Manganese (Approximately 110,000 mt pa) and Silico Manganese (Approximately 70,000 mt pa) from two 81MVA furnaces. For more information, please visit www.sakuraferroalloys.co.my