Evaluation methods of man-machine-environment system for clean and safe production in phosphorus mines: A case study

Phosphorus is an essential element in agricultural production and chemical industry. However, since the risk of casualties and economic loss by mining accidents, the application of clean and safe production in phosphorus mines encounters great challenges. For this purpose, a man-machine-environment system composed of evaluation indexes was established, and the grading standards of indexes were defined. Firstly, the measurements of 39 qualitative indexes were obtained through the survey data. According to the measured values of 31 quantitative indexes, the measurements of quantitative indexes were calculated by linear measurement function(LM) and other three functions. Then the singleindex measurement evaluation matrixes were established. Secondly, the entropy weight method was used to determine the weights of each index directly. The analytic hierarchy process(AHP) was also applied to calculate the weights of index and index factor hierarchies after the established hierarchical model. The weights of system hierarchies were given by the grid-based fuzzy Borda method(GFB). The comprehensive weights were determined by the combination method of AHP and GFB(CAG). Furthermore, the multi-index comprehensive measurement evaluation vectors were obtained.Thirdly, the vectors were evaluated by the credible degree recognition(CDR) and the maximum membership(TMM)criteria. Based on the above functions, methods, and criteria, 16 combination evaluation methods were recommended.Finally, the clean and safe production grade of Kaiyang phosphate mine in China was evaluated. The results show that the LM-CAG-CDR is the most reasonable method, which can not only determine the clean and safe production grade of phosphorus mines, but also improve the development level of clean and safe mining of phosphorus mines for guidance.In addition, some beneficial suggestions and measures were also proposed to advance the clean and safe production grade of Kaiyang phosphorus mine.

Clean and Safe Supply of Fish and Shellfish to Clear the HACCP Regulation by Use of Clean and Cold Deep Ocean Water in Rausu,Hokkaido,Japan

For the supply of fish and shellfish to consumers in fresh condition, clean handling after catch from the sea is essential. According to HACCP （Hazard Analysis and Critical Control Points）, it is important to meet such requirement by keeping fish and shellfish under a certain low temperature and clean conditions after catching. The deep ocean water （DOW） characterized by low temperature and cleanliness has been chosen for fish and shellfish handlings, particularly for salmon, cod, and sea urchin in Town ＇Rausu＇ in Hokkaido, Japan. DOW below 2.9℃ of an amount of nearly 5 000 m^3 is planned to be pumped up every day from a depth of about 350 m, and temporarily stored in a large simulated tank on land. DOW is then supplied to fish boats through hydrants distributed throughout the harbor and used for keeping salmon in clean and cold conditions. Ice made from DOW is also used for lowering temperature if necessary. DOW and ice made from DOW are also used during the transportation of fish and shellfish. The entire system is scheduled to be completed by the summer of 2005.