Maputo Corridor Logistics Initiative

Members – Manganese Metal Company (MMC)

Manganese Metal Company

Manganese Metal Company (MMC)

Contact Details

  • Shirley Moshikidi Mnisi  or  Jackie McGee
  • +27 13 759 4600
  • Visit Website

Introduction

Manganese Metal Company (MMC) is the single largest producer of pure electrolytic manganese metal in the world. MMC produces only selenium-free electrolytic manganese - the purest form of manganese - to meet the specialised needs of our customers around the world. The production facility is located in Nelspruit, in the Mpumalanga province of South Africa. The metal is produced from South African high-grade manganese ore, extracted via a hydrometallurgical process. From the metal a range of products is manufactured and packaged according to individual customer requirements, then shipped mainly via the ports of Durban and Maputo. The use of a selenium-free process technology ensures 99.9% minimum metallic purity for our products and it facilitates sustainable development of the company in terms of human health and environmental safety.

MMC has been producing pure electrolytic manganese since 1960. The production capacity is 30,000 tonnes per annum, from a single cellhouse, equipped to pass 56,000A current. MMC is an ISO 9001:2008, ISO 14001:2004 and OHSAS 18001:2007 certified company. MMC is the preferred supplier of pure electrolytic manganese metal to a global market.

Products

Chromium Aluminium Briquettes

Electrolytic Manganese Metal Low Hydrogen Flake

Electrolytic Manganese Metal Low Oxygen Flake

Electrolytic Manganese Metal Stabilised Powder (SP-40+325#)

Electrolytic Manganese Metal Stabilised Powder (SP-60+325#)

Electrolytic Manganese Metal Unstabilised Powder (UP-40+325#)

Electrolytic Manganese Metal Unstabilised Powder (UP-60+325#)

High Density Manganese Briquettes

Manganese Aluminium Briquettes 75%

Manganese Aluminium Briquettes 85%

Mangano Manganic Oxide (Mn3O4)

Nitrided Manganese Briquettes

Nitrided Manganese Flakes

Process Flow Description

The extraction process begins with high-grade ore, mined in the Kalahari. The ore is milled to a powder and then it is reduced to a soluble form in rotary kilns. The reduced ore is dissolved in acid solution, followed by purification (precipitation of impurities and filtration). Sulphur dioxide, and not selenium dioxide, is added to the purified solution before electrolysis can take place. The solution is then fed into the electrolytic cells, where electric current causes the manganese to plate on the cathodes. Pure manganese metal is plated on the cathodes, while sulphuric acid, formed at the anodes, is re-cycled back to the dissolution process. The plated manganese is stripped from the cathodes, washed, dried and degassed. This metal is manganese in its purest, cleanest form. Depending individual customer requirements, the metal is then processed further and packaged for shipment.

The solid waste remaining after dissolving the manganese is filtered to recover manganese- and ammonium sulphates to obtain a dry cake for disposal. MMC’s holds permits to operate a hazardous landfill facility at Kingston Vale. The Kingston Vale landfill design includes liners with leakage detection and filter trenches to collect all rain run-off. After collection the liquid is passed through MMC’s evaporation plant.

Liquid effluents are treated to ensure that no contaminated water leaves the MMC site. Rainwater is also collected and passed through the same treatment plant, where dissolved metals are precipitated and filtered out, then stripped of ammonia.

MMC’s total process flow is designed to produce a high purity, selenium-free product while limiting the impact on the environment and protecting the health of its employees.

Selenium Free Process

Manganese Metal Company (MMC) employs a selenium free process

Selenium free manganese (99.9% Mn) is purer, safer and more environmentally friendly than selenium containing manganese (99.7% Mn).

Selenium is one of the 12 most hazardous substances as defined by the EPA-TCLP test. Adding selenium to the electrolytic manganese manufacturing process, improves the efficiency with which electricity is utilized to convert manganese in solution to manganese metal.

Although a possible production cost saving, MMC has decided not to use the selenium technology as the short term cost benefit is far outweighed by the risk of poisoning our and our customer's employees, rivers, skies and farmlands.

There are also additional costs associated with the treatment and disposal facilities necessary to comply with the environmental regulations associated with selenium.