Product Stewardship in Wollastonite Production

Abstract

In July 2002, NYCO Minerals, Inc., discovered a heretofore unknown contaminant in its wollastonite ore. The contaminant was first believed to be tremolite asbestos. Immediate efforts were made to eliminate this material. Additional studies were initiated to fully characterize the contaminant and its distribution in the ore body. Subsequent study by NYCO and their consultants led to the identification of the contaminant as a transition material (TM) intermediate between tremolite and talc. In vitro dissolution rate measurements indicated that the TM dissolved much more rapidly than tremolite asbestos. This article provides background information on wollastonite mineralogy and NYCO's product stewardship program (PSP). At present, NYCO Minerals uses selective mining to control the trace levels of TM in the ore and finished product verified by periodic monitoring of workplace air and finished product.NYCO Minerals, Inc., developed a product stewardship program (PSP) to identify, manage, and control occupational risks associated with the production and use of wollastonite. This article presents a short case history of the discovery, identification, and control of what was initially considered to be a potentially

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Silicon Use in the Integrated Disease Management of Wheat: Current Knowledge

“…In this context, the most common Si fertilizers are wollastonite and slag (calcium silicate). In the case of wollastonite which is a natural calcium silicate [42], that contains higher fractions of easily soluble Si compared to slags [40]. It is considered to be the most efficient Si fertilizer for soil application due to that it can release the largest amount of plant available Si (2.31-3.6%) into soil solution [43,44]; however, its use is often limited because of its relatively high cost [45].…”