AXIS HOUSE – UNDERSTANDING AND DEVELOPMENT OF REAGENTS & MINERAL AFFINITY
Mining Review Journal Zambia
The core business of Axis House has always been to understand the needs of our mineral processing clients and to address those needs with quality products, people and service. Since being established, Axis House has become a major supplier and distributor of chemicals to the mining industry, with clients in Zambia and across the globe.
Axis House has been supplying novel flotation and hydrometallurgical reagents for copper and cobalt processing since inception. The AMTM series of Hydroxamate collectors, together with tailored secondary collectors, depressants and HydrofrothTM frothers have been implemented in many operations to successfully recover base metal oxides and sulphides. With ongoing research and developments, the Axis house range of reagents is constantly expanding into new commodities. New developments and existing reagents have been applied in the flotation of Platinum Group Metals (PGM), Rare Earth Oxide, Phosphate and Lithium bearing ores.
The technical laboratory which is based in Cape Town, works closely with the Axis House metallurgists who are active at the various operations in Africa, South America, Europe and Central Asia. The focus of the collaboration is to fully understand the ore, the process and operational targets, thus being able to provide tailored solutions to clients to reach those targets. With this approach, various ore types can be sourced, studied and a reagent solution developed. The performance of reagents is always tested and verified on a laboratory scale before commencing with onsite trials. Thus, plant trials are entered with clear goals and expectations.
Developments in Zambia
The last couple of years have brought some exciting new developments in Zambia for Axis House as the supplier of flotation reagents and flocculants to the mining industry. Due to the importance of selecting the correct reagent programme and its application, our approach is to understand the current situation with the view of identifying areas where improvements can be made. The ultimate benefit being an overall increase in production efficiency. As a result of this approach to our clients, Axis House employs a full time Zambian metallurgist who is based in Chingola, who has the backup of our fully equipped R&D laboratory in Cape Town. This ensures our clients are supported on a technical and commercial level.
Managing our clients’ supply chain on some of their larger consumed commodities has been well received and utilised in Zambia. Axis House holds substantial quantities of stock in Durban and Walvis Bay to offer continuity of supply, enabling our clients to hold smaller volumes on site, thereby minimising their stockholding on their balance sheet and reducing risk of over stock positions on site. We take monthly stock takes, check daily consumptions and keep a close eye on any spikes or drops in consumption to maintain a healthy stock level on site.
Zambian ore’s are mostly sulphides with 5-15% oxides. The major sulphide minerals are Chalcopyrite and Chalcocite with silica insoluble and carbon as the major gangue.
Our R&D found different solutions to each problem faced on site such as the selective flotation of valuable minerals or rejection of particular gangue.
Collectors were designed to give better selectivity of hydrophobic minerals against unwanted gangue contaminants. We focused on rejection upfront, early in the process. Other routes taken to reduce unwanted gangue is through the use of depressants which help change the surface charge and hydrophobicity of the gangue.
Axis House technology has benefited the Zambian copper industry in numerous ways. Operations with dirty thickener overflows recycle water back to the head of the process, resulting in lower copper grades and higher reagent consumptions. Using the right Axis House technology this allowed the plants to operate with clean recycled water.
The larger operations with pyrite or insoluble silicas have benefited through tailored collectors and frothers which rejected these unwanted gangue minerals upfront in the roughing stages, allowing for cleaner concentrates, reduced recycle streams and concentrate within smelter-required specifications.