COM 2022: 61st Annual Conference of Metallurgists
Toward carbon negative cement and battery materials
Abstract. Decarbonization is the challenge of the century. Carbon-negative materials production and supply chains can be part of the solution. Negative Emissions Materials, Inc (NEM) has developed a process for production of carbon-negative nickel and cobalt battery material intermediates using a chloride based hydrometallurgical process route applied to saprolite ores. Amorphous silica, a supplementary cementitious material that can reduce the clinker content of cement mixes by 30%, is a coproduct. Magnesium hydroxide, a specialty chemical with several environmental applications, is the other major coproduct of the NEM process. The NEM process uses HCl leaching of saprolite to produce the silica residue, and the leachate is neutralized to produce an iron/aluminum/chromium residue as a potential coproduct. The iron-free solution is further neutralized to produce a mixed hydroxide precipitate (MHP) of nickel and cobalt followed by a high-purity magnesium hydroxide precipitate. The final solution is a concentrated sodium chloride solution which is directed to chloralkali processing to produce HCl and NaOH for acid leaching and neutralization. The process has advanced quickly through bench and pilot testing and is moving toward the development of the first large-scale demonstration plant. The pro- cess and the supporting testing will be presented.