Research On The Technique Of Flotation Impurity With The Containing Asbestos Talc

The talc containing asbestos has become a problem of life and death to the talc industry, talc including asbestos is also believed to cause cancer. Countries formulate and use more and more strict standards of detecting asbestos in the talc to ensure the talc not harm to health of human beings and the environment. It greatly influences the exports of the talc ore, another the content of CaO is higher in talc of having asbestos. The talcum powder applying in the Plastic, cosmetic, medicine-food and high-grade ceramic requirements content of CaO, The talcum powder applying in cosmetics level, food and medicine grade requirements not to detect the asbestos, while the content of CaO in the high range plastic packing and ceramics is very low, commonly below1%. Therefore, it has the very high economic value.to flotation and purification the talc containing asbestos.Natural flotability of talc, tremolite, and dolomite in the three different flotation as well as the influence of metal ions, inorganic regulators, organic depressants to the flotability of pure minerals in the SDBS flotation are studyed in this paper. The flotation separation of mixed minerals and actural minerals is also investigated sysmatically. Then, a new flowsheet to handle this kind talc ore is proposed, namely "one roughing-three cleaning-one scavenging", We are led to one conclusion:The flotation separation tests of pure minerals indicate that adding phytic acid and calgon can increase flotation of different minerals under different pH value with the SDBS as collector. This mixed agent has a better role to the flotation separation of three kinds of single mineral.The tests demonstrate that in the ratio of talc:tremolite:dolomite is8:1:1, the grade of the SiO2of the concentrate is above61.8%, the recovery above80%, when the dosage of SDBS is240mg/L, and phytic acid or calgon is320mg/L and160mg/L; besides the grade of SiO2concentrate is reach to62.07%from54.95%, the recovery reach to75.67%, when the dosage of kerosene is7680mg/L, and2#oil is320mg/L. The closed-circle flotation test in laboratory can abtain a concentrate with the SiO2and CaO grade of the concentrate is61.87%and0.60%, the SiO2recovery is72.59%by "one roughing-three cleaning-one scavenging" process flows in the SDBS flotation, when the depressant is phytic acid, the pH value is11, the grinding fineness is75%. The rate of removal of tremolite is95.85%. analysis of concentrate by SEM, it turns out to have not asbestos in the talc. The flotation products had also achieved Grade onetalcum powder basic request. They can be used in cosmetics, medicine, food,and plastic packing.Mechanism researches show that issolubility of dolomite is Large, its floatability is good in the SDBS flotation, in addition, Mg2+and Ca2+dissolved by the dolomite can strongly activate tremolite in inalkaline conditions. So the key point of flotation impurity with the containing asbestos talc is selecting a device for inhibiting dolomite and tremolite flotation reagent.The Mg2+concentration exposed in the surface of the talc is lesser than the Mg2+and Ca2+concentration exposed in the surface of the dolomite and tremolite, Thus, phytic acid and calgon have more effective against the dolomite and tremolite than the talc.The research provide the foundation for the industrial application of flotation impurity with the containing asbestos talc.