Grinding chemicals

G. C. Lowrison, Crushing and Grinding Chemical Rubber Co., Boca Raton, Fla., 1974. 

Ratcliffe, A. Crushing and Grinding, Chemical Engineering, July 10, 1972, p. 62. 

A study on workers in a bearing manufacturing plant revealed significant excesses in proportional mortality ratios (PMR) from stomach cancer (PMR=2.0) and rectal cancer (PMR=3.1) among white male workers. Significant association was established between stomach cancer with precision grinding chemicals such as the water-based cutting oils and their aerosols [19]. 

For the pm-pose of this article, chemistry is considered to be the science of the transformation of substances, including transformations that do not involve cheirucal reactions (such as distillation or grinding). Chemical engineering science is the discipline concerned with the mechanical, physical, physicochemical, and chemical aspects of aU (industrial) processes in which substances are transformed. Processes in chemical plants are not only dependent on chemical events, but also (and often predominantly) determined by transport phenomena (momentum, heat, and mass transfer). Knowledge of combined mass, heat, and momentum transfer is crucial to chemical engineering. For a chemical reaction to proceed. 

Workers in the metals treatment industry are exposed to fumes, dusts, and mists containing metals and metal compounds, as well as to various chemicals from sources such as grinding wheels and lubricants. Exposure can be by inhalation, ingestion, or skin contact. Historically, metal toxicology was concerned with overt effects such as abdominal coHc from lead toxicity. Because of the occupational health and safety standards of the 1990s such effects are rare. Subtie, chronic, or long-term effects of metals treatment exposure are under study. An index to safety precautions for various metal treatment processes is available (6). As additional information is gained, standards are adjusted. 

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