Charles Butters graduated as a mining engineer at the University of California in 1879 and during the next ten years worked as a mining metallurgist in the United States and other parts of the world. In 1889 he accepted a post as metallurgist on the Witwatersrand which had been offered to him by J. Hennen Jennings*, consulting engineer for H. Eckstein & Co. of Johannesburg. The gold mining industry was experiencing serious difficulties in extracting gold from pyritic ores and Jennings hoped that Butters, a first-class metallurgist, might be able to help solve the problem. Butters arrived in 1890 and was given the task of supervising the construction of a chlorination plant to treat pyritic ores at the Robinson Mine. At the end of the year he attended a demonstration of the cyanide process of gold extraction and became convinced that it provided the only answer to the problem. He recommended that H. Eckstein & Co. buy the rights to this process in South Africa, but this did not happen. However, he was able to design and erect a cyanide plant at Robinson Mine and played an important role in establishing the process on the Witwatersrand. With J.E. Clennell* he published two papers, in French, on the extraction of gold with cyanide in 1893 and 1894.
In 1894 Butters resigned from H. Eckstein & Co. and took a leading part in establishing the Rand Central Ore Reduction Company. With Edgar Smart* as co-author, he wrote an extensive paper on "Plant for the extraction of gold by the cyanide process...", which was published in the Minutes of Proceedings of the Institution of Civil Engineers (1894/5). In January 1896 he was arrested as an accomplice in the Jameson Raid, found guilty, and fined 2000 pounds sterling. He returned from a visit to the United States in April 1897 and three months later was elected president of the Chemical and Metallurgical Society of South Africa for 1897/8. He became a foundation member of this society in 1894, and served on its council in 1894/5 and 1895/6. He was also a member of the Geological Society of South Africa at this time, and joined the South African Association of Engineers and Architects in September 1897.
Butters's presidential address to the Chemical and Metallurgical Society of South Africa, which he read on 17 July 1897, dealt with the history of metallurgy and chemistry in the Transvaal, mainly in the gold mining industry (Proceedings, Vol. 2, pp. 78-86). In September that same year he read a paper on "By-products in the gold industry" (Vol. 2, pp. 126-136), and in February 1898 his presidential valedictory address dealt with "The economic treatment of slimes [i.e., fine tailings]" (Vol. 2, pp. 238-257). In 1905 he was still a member of the society's successor, the Chemical, Metallurgical and Mining Society of South Africa. He was the first metallurgist of importance on the Witwatersrand, and his role in developing the technique for recovering gold from slimes was probably his major contribution to South African metallurgy.
Butters left South Africa in March 1898 to return to the United States. By the end of the year he had obtained a lease on one of the great mill tailings dumps on the Constock lode in that country and was experimenting with its treatment by the Siemens-Halske electrolytic process, then already successfully in use in South Africa for recovering gold from potassium cyanide solutions. He established the firm Charles Butters and Co. in Virginia City, Nevada. In 1903 he and A.F. Crank wrote a paper on "A system of handling sand mechanically, for cyanide vats" for a meeting of the (British) Institution of Mining and Metallurgy. The paper was mainly a description of the Blaisdell excavator. He was the inventor of the Butters filter, used widely in gold mines, and the first to apply flotation techniques in the United States and Mexico. As a member of the (British) Institution of Mining and Metallurgy he was awarded its gold medal for research in the metallurgy of gold in 1906. Around that time he was working as a metallurgist in London. In 1927 he was almost executed by a firing squad in Nicaragua while protecting his mining holdings there. Four years later he received a medal from the Mining and Metallurgical Society of Freiburg, Germany, in recognition of his research in metallurgy. He was a millionaire at the time of his death in 1933.