Lead concentrates commercial specifications

The objective of this stage is to remove the traces of heavy metals contained in the concentrated raffinate, so that the ammonium salts comply with commercial specifications. The purification process consists of the precipitation of metallic sulphides by adding sodium sulphide to the concentrated raffinate. The generated suspension is filtered, leaving a mixture of ammonium sulphate and chloride concentrated solution, that is pumped to the fertilizer plant (fertlizer operations). The solid residue recycled to the lead smelter. The operating conditions are ... 

The limitations of ELISA methods include the specificity of antibodies, the concentrations of primary antibody and antigen, and the type of reaction solution. Nonspecific binding of either of the antibodies to related antigens, unrelated proteins of other bacteria, or even the microtiter plate may lead to false positive reactions.49,52 57 Use of a monoclonal antibody may decrease crossreactivity with other antigens. For detection of low numbers of bacteria, as in drinking water, the sample may be filtered to concentrate the cells or cultured in a selective broth until it reaches the minimum detection limit for ELISA.49,58 Commercial test kits using dipsticks, immunoblots, and sandwich ELISA methods have been developed for the identification of pathogenic bacteria.58,59... 

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