化德硅藻土选矿工艺研究

以化德硅藻原矿为原料，采用物理擦洗-离心和硫酸酸浸联合工艺进行硅藻土选矿试验研究，分别探讨了擦洗时间、擦洗质量分数、擦洗分散剂用量、擦洗pH值、离心时间、离心转速及酸浸温度、酸浸时间、硫酸浓度、液固比对硅藻土纯度和白度的影响规律，并对选矿后硅藻精土样品的白度、矿物成分、化学成分及颗粒形貌等进行表征。结果表明，硅藻土物理选矿的适宜工艺条件是：擦洗时间40 min、擦洗质量分数30%、分散剂用量0.5%、擦洗pH值为10、离心时间5 min、离心转速2000 r/min；酸浸最适宜工艺条件为：酸浸时间4 h、酸浸温度98℃、液固比2.5∶1(mL/g)、硫酸浓度5 mol/L；通过物理和化学联合选矿能有效去除黏土类矿物和石英、长石等杂质，硅藻土白度从64.5%提高到82.4%，二氧化硅含量从78.57%提高到92.83%。

Research and Performance Characterization of Puriifcation for the Huade Diatomite

Using Huade diatomite ore as raw material, the physical cleaning-centrifugal and sulfuric acid leaching process were proposed for diatomite puriifcation. The effects of scrubbing time, pulp concentration, dispersant dosage, pH value, acid leaching temperature, soaking time, sulfuric acid concentration, liquid-solid ratio on diatomite whitening were systematically analyzed. And the whiteness, chemical composition, mineral composition and morphology of acid leaching diatomite samples were also studied. According to the experimental results, the optimum puriifcation conditions for diatomaceous earth were obtained as follows: 40 min of scrubing time, 30% of scrub concentration, 0.5% of dispersants dosage, pH=10. The most optimum conditions for acid leaching process were as follows: 98℃ of soaking temperature for 4 h, 5 mol/L of sulfuric acid concentration, 2.5∶1 (mL/g) of liquid-solid ratio. Through the combination of physical and chemical process, the impurities such as clay minerals, quartz and feldspar can be effectively removed. Diatomite and silica content can be increased from 64.5% to 82.4%. And the SiO2 content of diatomite was improved from 78.57% to 92.83%.