Optimization of Lithium Extraction from Lepidolite by Roasting Using Sodium and Calcium Sulfates

The lithium extraction from a lepidolite concentrate using roasting, followed by water leaching, was studied. Several alternative additives were initially tested. The use of sodium and calcium sulfates as additives was evaluated in more detail. The influence of some process variables, namely the roasting time, roasting temperature and the additive/concentrate mass ratio, was studied applying a design of experiments. The lithium extraction was modelled and the fitted and validated model was used to optimize the process response. The increase in the additive/concentrate mass ratio, roasting time and temperature seems to result in solid state reactions and transformations that lead to phase, morphological and particle size distribution modifications, which were assessed by XRPD, SEM, and particle size analyses. In this process, lithium sodium sulfate formation constitutes a crucial step enabling the Li water leaching. High lithium extractions were estimated for several combinations of factors. At 850°C, lithium extractions over 90% are obtained when the roasting time is above 1.90 hour and the additive/concentrate mass ratios are over 0.77. An increase in the temperature to 875°C also leads to lithium extractions over 90% for a roasting time of 1 hour and an additive/concentrate mass ratio of 0.60.     

用硫酸烧结渣生产磁铁矿粉的探析

通过对生产磁铁矿粉的原料、工艺等分析,探析了利用硫酸烧渣生产磁铁矿粉的必要性和和可行性。     

菊糖硫酸化改性研究

采用三氧化硫-吡啶法对菊糖进行硫酸化改性,以取代度为指标,对反应温度、反应时间、物料质量比以及反应溶剂量进行工艺优化,确定了适宜的修饰条件为:反应温度为95℃、反应时间为4h,菊糖与三氧化硫-吡啶的质量比为1:4,吡啶25mL,此时取代度为2.81。对改性菊糖的红外和紫外光谱分析表明,菊糖分子上引入了硫酸酯基团。     

共生铅-锌混合精矿硫酸化焙烧分离铅、锌研究

采用硫酸化焙烧工艺对某共生铅-锌混合精矿进行了铅锌分离试验研究。在硫酸化焙烧过程中, 硫化铅和硫化锌与氧气反应生成硫酸铅和硫酸锌; 利用硫酸锌易溶于水、硫酸铅不溶于水的特性, 采用水浸工艺对焙烧产品进行铅、锌分离。结果表明: 在焙烧物料球团直径小于8.0 mm、空气流量1.0 L/min、焙烧温度650 ℃、焙烧时间2.5 h、硫酸钠用量2.4%、硫酸钙用量3.6%、常温常压下浸出1.5 h、浸出液固比1.5∶1, 得到了锌浸出率96.05%～96.68%、平均96.35%, 铅渣品位56.89%～57.25%、平均57.11%的指标, 铅、锌分离效果明显。     

常压硫酸焙烧法提取镍磷铁中的镍

采用硫酸化焙烧再水浸的方法从钙镁磷肥的副产物镍磷铁中提取镍,重点研究了提镍过程中相关因素对镍浸出率的影响。结果表明,在酸料比0.5、焙烧温度300℃、焙烧时间3h、水浸液固比7∶1、水浸温度70℃、水浸时间2.5h的条件下,浸出效果最好,浸出液中镍浸出率达到73.43%。     

蓖麻油硫酸酯化新方法的研究

通过对各种磺化剂的性能对比，选定以氨基磺酸作为蓖麻油的硫酸酯化剂，经过探索性试验和正交优化，得出本反应的优选条件为：物料配比n(OH)：n(H2NSO3H)为2：1；反应温度为105℃；反应时间为2．5h；催化剂用量为油质量的5％。该反应无“三废”产生，符合绿色化生产要求，是蓖麻油硫酸化的新途径，采用该方法试制出了性能优良的改性蓖麻油皮革加脂剂。     

石煤钒矿提钒新工艺研究

硫酸化焙烧-水浸提取石煤钒矿中钒的工艺是可行的,且工艺的适应性强、简单,易于产业化,是一种新的提钒技术。石煤钒矿硫酸化焙烧合适工艺技术为硫酸配入量35％、焙烧温度300℃和焙烧时间0．5h,钒的浸出率〉92％。     

钴硫精矿的硫酸化焙烧浸出研究

针对含钴高、含硫低且有相当数量铜的钴硫精矿进行焙烧-浸出,考察了焙烧温度、焙烧时间、添加剂用量、浸出时间、浸出温度及液固比等对铜和钴浸出率的影响。结果表明,钴硫精矿混合均匀后以2.7℃/min升温至620℃,焙烧3h,焙砂在80℃、用30g/L硫酸33%矿浆浓度浸出2h,钴、铜的浸出率分别为91%、90%。     

提高某厂铅烟灰铟浸出率的研究

对某厂铅烟灰提铟工艺进行了研究,提出了硫酸化焙烧－水浸的浸出工艺流程,使铟的浸出率提高到88％以上。     

复杂高含铟物料铟浸出工艺研究

某铅冶炼厂的复杂高含铟物料为冶炼的中间产物,此物料采用常规酸浸工艺铟的浸出率较低.针对此问题,本文采用盐酸-硫酸混酸浸出、加压酸浸法、硫酸化焙烧-低酸浸出等3种工艺对此复杂高含铟物料进行了试验,在各试验的较佳工艺条件下,试验结果为:采用盐酸-硫酸混酸浸出工艺,铟的浸出率可以达到75.87％,浸出渣铟含量可以降低至0.3...