Experimental Studies for Feasibility of Manufacturing of Synthetic Stibnite for Ammunition Primer Feedstock

The synthesis of antimony trisulfide (Sb2S3, the mineral stibnite) materials with well-controlled size, crystallinity and chemical purity is important in manufacturing for numerous electronics, munitions, solar, and chip-doping applications. Crystal growth methods have evolved considerably over the past few decades, primarily as an outgrowth from the electronics, solar energy and chip manufacturing industries. It is likely that some, but not all of these methods may have the potential to be scaled up into a cost-efficient large-scale process to manufacture crystalline antimony trisulfide to meet specifications for military primer material preparation utilizing more efficient and effective methods. Specific attempts to manufacture “synthetic” crystalline stibnite from high purity refined antimony metal and high purity sulfur has reportedly been tried periodically by ammunition primer manufacturers with mixed success.  The proposed project consists of two components with work to be conducted by experienced materials science investigators at the South Dakota School of Mines and Technology in collaboration with the SBC.  The first consists of a thorough literature review to evaluate and screen possible methods already in use in other industrial sectors to produce antimony trisulfide crystals or other sulfides. Results of the literature review will inform the selection of a candidate group of methodologies for a second component of work that will include preliminary laboratory investigations for feasibility of the techniques for more cost-efficient primer feedstock material manufacture.  Follow-up efforts to accomplish this would likely include a series of laboratory tests to investigate the range of temperatures and pressures (both for heating and cooling) needed to optimize stibnite crystal grain growth with the optimum crystallinity, chemical composition and grain size for primer manufacturing. Once laboratory testing helps determine the range, further larger scale testing could be undertaken in a Phase II project to develop a full-scale pilot plant to test the process and output. The anticipated schedule for this first phase is estimated to be less than or equal to 6-months depending on outcome of preliminary studies.