Treatment of wastewaters from ore flotation containing aliphatic amines and hydrofluoric acid

Wastewaters from feldspar flotation containing hydrofluoric acid and amines were effectively purified by neutralization‐clarification with a 10% solution of lime and polyelectrolytes, followed by a coke filtration and/or a Zeolite or Activated Alumina adsorption. A Polish synthetic Ca‐type Zeolite proved to be efficient in the elimination of fluoride ions at the pH of 7.8. At this pH the Zeolite was more efficient than the Activated Alumina N. Wastewaters from feldspar washing were effectively treated by coagulation with A1₂(SO₄)₃, yielding final effluents with the characteristics very close to the clarified postilotation wastewaters. After clarification amines and fluoride ions could be removed from feldspar postflotation and feldspar washing effluents mixed together. A final concentration of fluorides and amines in the purified wastewaters was below 2 mg/1.     

江西盛源盆地橄榄玄粗岩系列火山岩长石矿物特征及成因信息

江西盛源盆地橄榄玄粗岩系列火山岩中的长石矿物特征为:斜长石斑晶具有反环带结构和交代净边结构,基质中存在大量的斜长石微晶,且在电子探针下研究发现基质中斜长石微晶具有钾长石环边的矿物学特点,为此类火山岩归属于橄榄玄粗岩系列火山岩提供了矿物学证据。通过对长石矿物组合特征进行研究,探讨该地区橄榄玄粗岩系列火山岩的成因以及成岩时的物理化学条件等方面的信息。     

改性长石对磷的吸附热力学和动力学研究

在500℃下对甘肃长石进行2 h煅烧,得到改性长石。通过批平衡实验,研究了改性长石对磷的吸附热力学和动力学性能。结果表明：改性长石对磷的吸附等温线符合Freundlich方程,且温度越高,吸附量越大。同时,在60 min内即可对10 mg/L磷溶液达到吸附平衡,改性长石对磷的吸附动力学符合准二级吸附动力学模型,主要是以化学吸附为主。     

Metal stabilization mechanism of incorporating lead-bearing sludge in kaolinite-based ceramics

The feasibility and mechanism of incorporating simulated lead-laden sludge into low-cost ceramic products was investigated by observing the reaction of lead with two kaolinite-based precursors under sintering conditions. To investigate the phase transformation process of lead, lead oxide (PbO) mixed with a kaolinite or mullite precursor were fired at 500-950 °C for 3 h. Detailed X-ray diffraction analysis of sintered products revealed that both precursors had crystallochemically incorporated lead into the lead feldspar (PbAl₂Si₂O₈) crystalline structure. By mixing lead oxide with kaolinite, lead feldspar begins to crystallize at 700 °C; maximum incorporation of lead into this structure occurred at 950 °C. However, two intermediate phases, Pb₄Al₄Si₃O₁₆ and a polymorph of lead feldspar, were detected at temperatures between 700 and 900 °C. By sintering lead oxide with the mullite precursor, lead feldspar was detected at temperatures above 750 °C, and an intermediate phase of Pb₄Al₄Si₃O₁₆ was observed in the temperature range of 750-900 °C. This study compared the lead leachabilities of PbO and lead feldspar using a prolonged leaching test (at pH 2.9 for 23 d) modified from the toxicity characteristic leaching procedure. The results indicate the superiority of lead feldspar in stabilizing lead and suggest a promising and reliable strategy to stabilize lead in ceramic products.