Previously known as African Chrome Mines, the present day Zimasco started operating in 1926 as an exporter of chromite ore.  In 1962, it started its first smelting operation and was re-named Windsor Ferro-Alloys.  After a year of operating, the company was purchased by Union Carbide Corporation and expansion of the smelting operations started in earnest. Between 1965 and 1972, Furnaces I, II, III and IV which today make up Kwekwe's West Plant were installed.

East Plant, comprising Furnaces V and VI was built between 1976 and 1980 and the two furnaces were commissioned in 1981 and 1984 respectively.

In 1980, the Zimbabwe Mining and Smelting Company (Pvt) Ltd which held all the Zimbabwean assets of Union Carbide was incorporated.  In 1994, Union Carbide completed a sales and management agreement whereby an experienced team of managers was appointed to run the operations.  This arrangement proved successful and subsequently, when Union Carbide decided to exit the mining business and concentrate on it's core business, this team purchased 100% of the Zimbabwe Mining and Smelting Company from Union Carbide Metals UK (Pvt) Ltd which owned 100% of Union Carbide Zimbabwe Ltd.

In 1995, a new holding company, Zimasco Consolidated Enterprises (ZCE) was set up in Mauritius and the Zimbabwe Company officially changed its name from Union Carbide Zimbabwe (Pvt) Ltd to Zimasco Holdings (Pvt) Ltd.

December 2007 heralded a new era in the life of Zimasco.  Sinosteel Corporation of China purchased 92% of Zimasco Consolidated Enterprises (ZCE). With 27% of ZCE having been previously localised through a special purpose vehicle, ZCE Finance, Sinosteel Corporation became the majority shareholder of Zimasco Holdings and in turn Zimasco (Pvt) Ltd.

With various share purchases since 2007, current ZCE Shareholding is 86.3% Sinosteel Corporation and 13.7% China-Africa Development Fund.

Sinosteel Corporation is a central enterprise under the administration of the Chinese State-Owned Assets Supervision and Administration Commission.  There are over 86 subsidiaries under the administration of Sinosteel Corporation Limited.  Sinosteel is mainly engaged in the development of metallurgical raw materials and products, related engineering technical services as well as equipment manufacture.