選鉱用水の循環使用に関する実験的考察 (第2報)

蓄積とプロセス性能

抄録

A series of there studies is concerned with operation of an are dressing plant with a closed circuit for water from a standpoint of reducing consumption of water and preservation of an environment from pollution by the waste water. The authors constructed the kaoline are processing pilot plant of closed circuit and experimented on the plant operation to be recycling the waste water. The previous paper reported the results of continuous water recycling operation which was conducted for long period at about 50 and 90% recycling ratio of the waste water. The mineral balanceand quality of concentrate was obtained from the results of the operation tests. This paper present the results on the investigation and discussion about the changes on standing of the accumulated materials in the closed system and the these effects on the process performance. The soluble materials which were accumulated in the system were little and the effect for the processes was fractionally in 50% recycling ratio. However, in the case of 90% ratio, the amount of soluble materials increased with a passage of time. The concentration of Fe³⁺ ion in recycling water reached nearly 7000 ppm, Na⁺ ion was 11000 ppm, TOC was 1300 ppm at the finish time of the experiment. It reduced gradually the separating performance by these accumulations. These soluble materials affected remarkably the processes of settling pond, flotator, bleaching and so on, and the quality of the concentrate. It became clear from the above mentioned that the closed systematization enabled to circulate within a certain acceptable value for the recycling ratio of the waste water.