Mineral feed assay

To separate solids having about the same particle size but with a different density, separate based on cut density and use Concentrators such as jigs, tables, sluices or Dense Media Separators, DMS. Particle diameter must be > 40 gm. Concentrate before flotation if the feed assay of mineral is < 0.3%. 

From the relative weights of the concentrate and the tailings and their assays, that fraction of a certain mineral or gangue contained in the feed or input material which is recovered in the concentrate can be obtained. This, defined earlier, is known as the recovery (R). When expressed as a percentage,... 

Minerals are usually analyzed by the traditional method of atomic absorption spectroscopy or with the newer induced coupled plasma analyzers. Most vitamins are analyzed by HPLC systems or colorimetric assays. Many laboratories still quantify folic acid with the use of a microbiological assay. The analysis of dietary and detergent (neutral and acid) fibers are critically important for foods and feeds, respectively. Raw materials and feeds should be examined for rodent contamination, pathogenic bacteria, molds and mycotoxins, and undesirable toxicants such as PCB, insecticides, herbicides, and heavy metals. The proper selection of ingredients will ensure the production of high-quality foods that satisfy sensory properties required for humans, and feeds that are palatable and can meet sensory properties required for domestic animals (Chapter 18). 

---