固氟氯化铵焙烧法从包头稀土矿中回收稀土的动力学

研究了固氟氯化铵焙烧法分解包头混合型稀土精矿回收稀土的动力学.结果表明:固氟焙砂的氯化反应过程符合Bagdasarym提出的区域反应速率模型,氯化反应过程经过了两个串联反应步骤,且反应生成物的核按一个方向长大;反应速率方程遵从Erofeev方程的串联反应步骤模型,反应表观活化能Ea为36.831 KJ·mol-1,过程控制步骤是内扩散控制.     

Reaction process of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2

The decomposition reactions of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2 were studied by means of TG-DTA and XRD. The results show that the process of the minerals decomposed by CaO involves two steps. The first step occurs in the temperature range of 425-540 ℃, and the main reactions are bastnaesite decomposition, i.e. REOF reacts with CaO to produce RE2O3 and CaF2, and Ce2O3 is oxidized to CeO2. During this step, CaCO3 is formed at about 500 ℃. The second step takes place in the temperature range of 610-700 ℃, and the reactions are monazite decomposition into RE2O3, Ca5F（PO4）3 and Ca3（PO4）2 by CaO and CaF2. In this process, the decomposition ability is improved because CaO from CaCO3 decomposing has high chemical activity. In calcining process, the new formed Ca5F（PO4）3 restrains fluorine that can escape in form of gaseous compound. The decomposition ratio of the mixed rare earth minerals reaches 90.8% at 700 ℃.     

Selective leaching of vanadium from V-Ti magnetite concentrates by pellet calcification roasting-H_2SO_4 leaching process

A novel method of pellet calcification roasting-H_2 SO_4 leaching was proposed to efficiently separate and extract vanadium(V) from vanadium-titanium(V-Ti) magnetite concentrates.The leaching rate of V is as high as 88.98%,while the leaching rate of impurity iron is only 1.79%.Moreover,the leached pellets can be used as raw materials for blast furnace ironmaking after secondary roasting.X-ray photoelectron spectroscopy(XPS) and scanning electron microscopy with energy dispersive X-ray spectrometry(SEMEDS) analyses showed that V~(3+) was oxidized to V~(5+) after roasting at 1200℃,and V~(5+) was then leached by H_2 SO_4.X-ray diffraction(XRD) analyses and single factor experiment revealed a minimal amount of dissolved Fe_2 O_3 during H_2 SO_4 leaching.Therefore,a high separation degree of V and iron(Fe) from V-Ti magnetite concentrate was achieved through H_2 SO_4 leaching.Compared with the traditional roastingleaching process,this process can achieve a high selectivity of V and Fe,and has excellent prospects for industrial production.     

30%三唑锡悬浮剂的研制及作用机理分析

[目的]解决30%三唑锡悬浮剂分散稳定性的问题。[方法]为提高30%三唑锡悬浮剂分散稳定性,采用流点法对不同类型的分散剂进行初步筛选并测试表面张力,通过测试SC粒径、Zeta电势、悬浮率、流变性能确定分散剂配比与用量并对分散稳定机理进行分析。[结果]与单一分散剂制备SC相比,聚羧酸盐分散剂SD-816和聚氧乙烯醚磷酸酯分散剂SD-208复配体系制备的SC性能较优,其表观黏度、Zeta电势、粒径和悬浮率分别为386 mPa·s、-37.2 mV、2.58μm及98.4%。并且提出了聚羧酸盐分散剂和聚氧乙烯醚磷酸酯分散剂对农药三唑锡可能的分散机理。[结论]聚羧酸盐SD-816和聚氧乙烯醚磷酸酯SD-208的复配体系可同时提供静电排斥作用和空间位阻,明显改善SC体系的悬浮稳定性。     

铁精矿粒度对球团强度的影响

以大红山、曼南坎和滇滩等精矿的粒度以及膨润土用量和润磨时间为因子,以生球落下强度、生球爆裂温度、预热球抗压强度和焙烧球抗压强度为评价指标,进行了五因子二次回归组合实验研究。结果表明:随着铁精矿小于0.074mm粒级含量的增加,生球爆裂温度下降,预热球和焙烧球抗压强度提高;当铁精矿小于0.074mm粒级含量小于75%(质量分数)时,生球落下强度逐渐上升,当小于0.074mm粒级含量为75%时,生球落下强度达到最大值,之后有下降趋势。并不是铁精矿粒度越细球团强度就会越好,铁精矿粒度还应该满足一个合适的粒度组成。     

锌精矿制酸三级旋风除尘器的设计与实践

介绍了锌精矿制酸系统采用三级旋风除尘器替代电除尘器的设计及运行情况。为了提高旋风除尘器的除尘效率，硫酸系统各工序作了适当调整。运行实践表明，三级旋风除尘器除尘效果良好，硫酸系统能长期稳定运行。     

微山稀土精矿经固氟后采用氯化铵法回收稀土

微山稀土精矿经固氟后，采用氯化铵法回收稀土. 通过单因素条件实验确定了矿物固氟和氯化焙烧的较宜条件：固氟温度为550℃，固氟剂用量与精矿质量比为1:20，固氟焙烧时间50 min; 氯化剂用量与精矿质量比为1.2:1，氯化焙烧温度480℃，氯化时间60 min. 在较宜条件下，稀土的浸出回收率在87.8%以上. 利用X射线衍射探讨了固氟过程中可能发生的反应.     

20％磷威乳油（沅化938）的配制

２０％磷威乳油（沅化９３８）是一种以有机磷、氨基甲酸酯类农药为有效成分的新的混配制剂，在防治棉蚜、棉铃虫、棉叶螨等方面的增效作用十分显著。它有击倒快、触杀作用强、广谱等特点。该乳油配方先进，独特，系国内首创。生产工艺简单，易于操作，产品性能稳定。     

用唐钢石人沟铁精矿生产超级精矿

以石人沟铁矿精矿粉为原料生产超级铁精矿，进行了磨矿—反浮选、分级—反浮选和分级—低磁场磁选等试验，并按磨矿—反浮选方案建成了生产超级铁精矿的选矿厂。实践证明阳离子反浮选是生产低硅高纯铁精矿的可靠工艺。     

国内甲胺磷生产技术进展

甲胺磷是一种广谱性有机磷杀虫剂，它是我国生产吨位最大的农药品种。本文从合成工艺路线、生产技术现状、现存技术问题及工艺改进等方面介绍了我国甲胺磷生产的技术进展。建议应有效地控制产量增加，着重收率和含量的提高。