磷酸浸取磷矿酸解液中提取稀土的研究

对磷酸浸取含稀土磷矿得到的酸解溶液中稀土萃取回收进行研究。通过对萃取剂的选择,萃取和反萃条件的试验优化选取,从脱钙后得到的粗磷酸中利用萃取剂P204进行萃取,当相比为2∶1,P204浓度2 mol/L时,经过六级萃取后,萃取率达到97.13%。在相比O/A=1∶1,以6 mol/L HCl进行反萃时,一级反萃率可达到50%以上,采用六级可达近90%。     

溶剂萃取法分离锌锰金属离子的实验研究

以软锰矿和锌精矿同槽酸浸取得到硫酸锌、硫酸锰混合液,研究了从混合溶液中萃取分离锌离子、锰离子的萃取剂的选择以及适宜的萃取条件.实验结果表明,磷酸二(2-乙基己基)酯(P204)萃取锌的能力优于磷酸三丁酯(TBP),在室温、相比A/O=2∶ 1、萃取时间10 min、萃取级数5级、溶液pH为4.0,P204的体积分数为40%时,萃取率达到95%,萃取相锌质量浓度为27.15 g/L.反萃液为0.8 mol/L的稀硫酸,4级反萃,反萃液锌质量浓度可达到89.9 g/L,在此基础上提出了从软锰矿和锌精矿同槽酸浸取液中用P204萃取锌的工艺.     

中空纤维支撑液膜萃取法提铟工艺比较研究

采用中空纤维支撑液膜(SLM)技术,模拟酸性铟渣浸出液,以磷酸二异辛酯(P204)、磺化煤油体积比3:7为液膜萃取相,盐酸溶液为反萃相,研究了单组件膜萃取系统、双膜组件萃取-反萃系统、双膜组件萃取-超滤系统对酸性浸出液中In的提取与分离效率。结果表明,双膜组件萃取-超滤技术可同时实现浸出液中In的提取与反萃液中In的高纯度富集,浸出液中In的提取率可达90%以上,反萃液中In含量可达浸出液中In含量的70%,In的质量分数高于90%。     

湿法炼锌酸浸渣离子交换法富集回收锌中试研究

采用离子交换工艺,对湿法炼锌酸浸渣中的水溶性锌进行富集回收中试试验。工艺过程包括酸浸渣水浸和压滤洗涤、低浓度含锌溶液离子交换吸附解吸和转型、尾水循环利用等过程。中试结果表明,酸浸渣中水溶性锌浸出率为88.5%,渣中水溶性锌含量由3.75%降低到0.56%(以干渣计)。树脂平均吸附容量为118 kg Zn/吨湿树脂,以酸性含锌电解液作为解吸剂,回收的锌离子可以富集到83.3 g/L左右,离子交换树脂转型剂为80 g/L的氢氧化钠溶液。     

从废弃防腐涂料中回收锌的工艺研究

以废弃防腐涂料为原料,在湿法冶金工艺的基础上,结合原料特点,提出酸浸-萃取-电积的湿法冶炼清洁生产工艺回收废料中的金属锌。结果表明,最佳工艺条件:用浓度2 mol/L的硫酸溶液,浸取时间为2 h,浸取温度为25℃,液固比为15∶1的条件下,锌的浸出率为62.36%;在pH值为4,有机相配比为2∶8(质量分数20%的P204与80%煤油),油水相比为1∶1的条件下,萃取率可达48.48%。然后经过萃取和反萃可获得符合锌电积要求的硫酸锌溶液,最后电积得到锌粉(质量分数99.99%),回收率可达96.5%,是一种节能、经济、环保的新工艺。     

用氨配合法从含锌废催化剂中回收锌

针对氧化锌易溶于氨-碳酸氢铵混合溶液中生成锌氨配合物这一特点,采用含锌废催化剂为原料,经化浆、高剪切分散后加入氨-碳酸氢铵溶液浸取,通过沉淀除杂、锌粉置换和热解蒸氨得到碱式碳酸锌。考察了高剪切分散机剪切速率、反应温度、浸取剂pH和浸取时间对锌浸出率的影响。结果表明,在剪切速率为25 000 r/min、反应温度为328 K、浸取剂pH=7.5、浸取时间为2 h的条件下,锌浸出率可达90%以上,制备的碱式碳酸锌优于HG/T 2523—2007《工业碱式碳酸锌》标准要求。该研究综合利用了含锌废催化剂,无二次污染产生,符合清洁生产和资源合理利用的要求。     

络合萃取法对煤制气高浓度含酚废水的资源化处理

用磷酸三丁酯(TBP)为萃取剂和煤油为稀释剂,对煤制气过程中产生的高浓度含酚废水进行了络合萃取处理,并用氢氧化钠溶液为反萃取剂对负载有机相进行了反萃取。分别研究了废水pH、TBP体积分数对萃取及氢氧化钠溶液浓度对反萃取的影响,并对萃取和反萃取过程中有机相的重复使用问题进行了探讨。结果表明,当废水的pH为3～6时,萃取率可达90%以上,CODCr去除率达到80%以上;当氢氧化钠质量分数为4%～10%时,反萃取率可达80%以上;TBP-煤油有机相可在萃取和反萃的过程中多次重复使用。     

磷化渣的综合利用

磷化渣中含有大量的磷酸铁和磷酸锌，我们采用氟水络合浸出回收磷酸锌，碱水浸出回收磷酸锌后余渣中的磷酸铁，可制得磷酸三钠和氧化铁红。     

2-丁基-2-乙基-1,3-丙二醇从地下卤水中提硼的研究

研究了以2-丁基-2-乙基-1,3-丙二醇为萃取剂,三氯甲烷为稀释剂,从四川平落地下卤水中萃取提硼。通过萃取条件的考察和筛选,最终确定萃取剂浓度为1.0mol/L,相比为1∶1,萃取时间为10min,萃取级数为二级的最优萃硼条件,此时萃取率可达98.56%,萃取剂的饱和萃取容量达44.25g/L(以H3BO3计)。同时,探究了以氢氧化钠溶液作为反萃剂的最佳反萃条件:反萃剂浓度为0.3mol/L,反萃相比为1∶1,反萃时间为8min,反萃级数为二级,其反萃率达到95.49%。在最优萃取和反萃条件下,经两级萃取和两级反萃,硼酸的回收率达到94.87%。     

溶剂萃取磷尾矿酸解液中的H_3PO_4

以硫酸和盐酸的混合酸分解高镁磷尾矿获得的酸解液为原料,研究不同萃取条件和反萃条件对磷酸萃取率和反萃率的影响。结果表明,对蒸发结晶除杂后的酸解液采用正丁醇进行萃取时,当萃取温度为室温、萃取原液P2O5浓度为48%、萃取相比为3︰1、萃取时间为10min时,可达到较好的萃取效果。在此条件下,P2O5的萃取率可达68%以上。从有机相中进行H3PO4反萃时,反萃剂采用水,加入量为反萃前有机相体积的30%,反萃时间为5min,常温下进行反萃,P2O5的反萃率可达90%以上。反萃后获得的溶液H3PO4浓度达到50.49%,其它杂质含量均较低,说明采用溶剂萃取法从高镁磷尾矿酸解液中萃取磷酸是可行的。     

磷化渣废液除锌制备高纯度磷酸三钠

为了实现磷化渣碱溶后所得废液的综合利用,采用中和沉淀法和硫化钠沉淀法去除磷化渣废液中的杂质锌,对中和沉淀法和硫化钠沉淀法的工艺条件进行优化,并由此设计磷化渣废液除锌制备高纯度磷酸三钠的生产工艺。对于中和沉淀法,在反应体系pH=8.85,反应时间为10 min时,Zn2+去除率可达97.96%;对于硫化钠沉淀法,在反应体系pH=6.85,硫化钠投加量与Zn2+的摩尔比为1:1,反应时间为10 min时,Zn2+去除率可达99.80%。相比于中和沉淀法除锌制备磷酸三钠工艺,硫化钠沉淀法除锌制备磷酸三钠工艺具有更高的磷酸三钠纯度,为98.85%,固相产品中Zn2+含量更低,仅为0.0004%,符合化工行业分析纯标准。该工艺大幅度地回收了磷化渣废液中的PO43-离子和Na+离子,为实现磷化渣综合利用的工业化提供新思路。     

铜冶炼废渣脱硅工艺研究

以铜冶炼废渣[简称铜渣,主要成分为铁橄榄石（Fe₂SiO₄）]为原料,采用钠化焙烧的方法脱除废渣中的硅,研究了以氢氧化钠为钠化剂对铜渣脱硅的影响。首先采用正交实验探究了焙烧温度、矿碱质量比、焙烧时间等因素对铜渣脱硅的影响顺序,在此基础上采用单因素实验研究了铜渣脱硅的适宜工艺条件。结果表明：铜渣脱硅影响因素由大到小的顺序为焙烧温度、矿碱质量比、焙烧时间。铜渣脱硅的适宜工艺条件：焙烧温度为650 ℃,矿碱质量比为1∶1.75（氢氧化钠理论量的4.17倍）,焙烧时间为180 min。在此条件下铜渣钠化焙烧所得产物的水浸渣中二氧化硅的质量分数降至1.74%,脱硅率达到94.5%。焙烧产物及其水浸渣的X射线衍射分析表明,铜渣钠化焙烧脱硅的机理是铁橄榄石转化为铁酸钠和硅酸钠,铜渣中的铁最终以四氧化三铁的形式存在,硅以硅酸钠的形式脱除。     

化工管道连接法兰磷化工艺条件优化及磷化膜的耐蚀性

以化工管道连接使用的Q235钢法兰为研究对象,对其进行磷化处理以提高耐蚀性.采用正交试验法考察了磷酸二氢锌浓度、氟化钠浓度、硝酸镧浓度、磷化液温度和磷化时间对磷化膜耐CuSO4点蚀时间的影响,并通过极差分析得到最佳磷化工艺条件为:磷酸二氢锌浓度60 g/L、氟化钠浓度2.5 g/L、硝酸镧浓度40 mg/L、磷化液温度...     

氰化尾渣矿浆电解液中铁离子的萃取富集

采用二(2-乙基己基)磷酸酯(P204)-磺化煤油萃取体系从高硫酸氰化尾渣矿浆电解液中富集铁离子,重点研究了P204浓度、相比(O/A)、振荡时间、振荡频率及温度等对Fe³⁺萃取率的影响及其萃取过程。研究表明,在P204体积分数为25%、电解液pH为1.5、温度25℃、O/A=1∶1、振荡时间10 min、振荡频率180r/min的条件下,电解液中Fe³⁺的单级萃取率可达97.73%以上,饱和萃取容量可达到21.57g/L。Fe³⁺在有机相中的萃取富集主要归因于其与P204分子结构中羟基的阳离子交换反应以及磷酰基的配位反应,形成的配合物为FeSO₄A(HA)₃与FeA₃(HA)₃。在草酸1mol/L、O/A=1∶1、振荡时间10min、振荡频率190r/min的条件下,负载有机相中Fe³⁺的单级反萃率可达82.64%以上,反萃液中铁主要以[Fe(C₂O₄)_3<...     

Research on leaching rate enhancement and organic matter removal in wet-process phosphoric acid

In the process of wet-process phosphoric acid leaching, the product phosphoric acid appears black due to the incomplete carbonization of some organic matter. A novel type of catalytic oxidation wet-process phosphoric acid purification technology was proposed in this work. During the leaching process, the oxidant (H₂O₂) and catalyst (MnO₂) was added to form the peroxides such as ·OH and HO₂· in the transformation process, which can enhance the removal rate of organic matter and strengthen the leaching rate of phosphate rock. The different reaction conditions that affected the leaching rate of wet-phosphoric acid and the removal of organic matter were investigated. The results indicated that 96.9% of phosphate rock were leached under the optimum conditions of H₂O₂ dosage 0.08 ml/g, MnO₂/P mass ratio of 0.04, 80℃ and for 40 min. At the same time, the TOC remove rate reached 79%. The analysis mechanism showed that H₂O₂ will form H₃PO₄ · H₂O₂ peroxide with H₃PO₄ in the solution, and MnO₂ will react with it like Fenton to generate a large amount of ·OH, and then fully oxidized the black organic matter into CO₂ and H₂O. Organic matter “wrapped” on the surface of the phosphate rock is broken by ·OH, which promoted the leaching of phosphoric acid and enhanced the removal of organic matter.     

湿法磷酸浸出强化及有机质去除研究

在湿法磷酸浸出过程中由于部分有机物碳化不彻底,使产品磷酸呈现黑色。本文提出了一种新型的催化氧化湿法磷酸净化技术,即在湿法磷酸浸出过程中引入氧化剂（H₂O₂）及催化剂（MnO₂）,基于转化过程中形成的·\mathrm{O}\mathrm{H}和\mathrm{H}{\mathrm{O}}_{\mathrm{2}}·等过氧化物实现对有机物的去除与浸出过程的强化。重点考察不同反应条件对湿法磷酸浸出率及有机质去除的影响。结果表明,浸出时间为40 min、反应温度为80℃、H₂O₂用量为0.08 ml/g、催化剂与磷矿的质量比为0.04时,磷矿浸出率可达96.9%;同时测定得到的TOC去除率达到79%。分析机理可得,H₂O₂会与溶液中的H₃PO₄形成H₃PO₄·H₂O₂过氧化物,MnO₂与之发生类Fenton反应,产生大量·\mathrm{O}\mathrm{H},进而将黑色有机物充分氧化为CO₂和H₂O,打破有机物对磷矿颗粒表面的“包裹”,促进磷酸的浸出和有机物的去除。     

Selective removal of iron(III) from highly salted chloride acidic solutions by solvent extraction using di(2-ethylhexyl) phosphate

Metal ions including Fe³⁺, Ca²⁺, Mg²⁺, Ni²⁺, Co²⁺ and Cu²⁺ are commonly found in the leaching solution of laterite-nickel ores, and the pre-removal of Fe³⁺ is extremely important for the recovery of nickel and cobalt. Di(2-ethylhexyl)phosphate acid (D2EHPA) showed high extraction rate and selectivity of Fe³⁺ over other metal ions. The acidity of the aqueous solution is crucial to the extraction of Fe³⁺, and the stoichiometry ratio between Fe³⁺ and the extractant is 0.86:1.54. The enthalpy for the extraction of Fe³⁺ using D2EHPA was 19.50 kJ/mol. The extraction of Fe³⁺ was ≥99% under the optimized conditions after a three-stage solvent extraction process. The iron stripping effects of different reagents showed an order of H₂C₂O₄>NH₄HCO₃>HCl>NaCl>NaHCO₃>Na₂SO₃. The stripping of Fe was ≥99% under the optimized conditions using H₂C₂O₄ as a stripping reagent.     

磷石膏与铜尾渣的高效耦合固定/稳定化处理

磷石膏(PG)和铜尾渣(CSS)是磷化工和有色冶炼行业中产生的两种固废,含有大量可迁移性有害物质,在堆存过程中能对环境造成污染。向PG、CSS混合渣中添加CaO作为额外钙源、NaOH作为激发剂,加入约30%(质量分数)的水,搅拌均匀,通过机械压模制成固结体(PG-S),经过抗压测试和毒性浸出试验,结果表明:PG-S抗压强度可达到14.8 MPa; PG中的主要污染物$PO^{3-}_{4}$、F^-的固定率分别达到99.87%和92.13%,重金属锌、铅等有害物质的浸出浓度均能满足《污水综合排放标准》(GB 8978—1996)要求,实现了对PG、CSS的高效耦合固定/稳定化处理。通过XRD、SEM表征分析证明PG、CSS中的有害物质通过生成不溶物和胶凝包裹吸附而被固定。     

A novel method for extracting vanadium by low temperature sodium roasting from converter vanadium slag

Long-term high temperature in conventional vanadium extraction process would cause particles to be sintered and wrapped, thus reducing extraction efficiency of vanadium. Based on the purpose of directional conversion and process intensification, this work proposed a combination of low temperature sodium roasting and high efficiency selective oxidation leaching in vanadium extraction. The investigation of the reaction mechanism suggested that the structure of vanadium slag was changed by roasting, which also caused the fracture of spinel. The addition of MnO₂ promoted the directional oxidation of low-valent vanadium into high valence. It also found that Na₂S₂O₈ could oxidize low-valent vanadium effectively in leaching. The leaching efficiency of vanadium reached 87.74% under the optimum conditions, including a roasting temperature of 650 ℃, a roasting time of 2.0 h, a molar ratio of sodium-to-vanadium of 0.6, a MnO₂ (roasting additive) dosage of 5 wt% and a Na₂S₂O₈ (leaching oxidant) dosage of 5 wt%. This percentage is 7.18% higher than that of direct roasting-andleaching under the same conditions.     

Strength, pore structure and permeability of alkali-activated slag mortars

This paper deals with the strength development, pore structure development, rapid chloride permeability and water permeability of alkali-activated slag mortars activated by 6% (by mass of Na₂O) NaOH, Na₂CO₃ and Na₂SiO₃. The Na₂SiO₃-activated slag mortars exhibited the highest strength at both early and later ages, even much higher than a typical commercial Type III portland cement. NaOH-activated slag mortars exhibited the lowest strength. The pore structure measurements were consistent with strength results. Four common strength-porosity equations: Balshin's, Ryshkevitch's, Schiller's, and Hasselmann's equations, fit the experimental results from alkali-activated slag mortars with sufficient efficiency; of which Hasselmann's equation fit best. The charge passed through the mortar specimens in the rapid chloride ion permeability test appeared to be dependent more on the chemistry of pore solution than on the pore structure of the mortars. Limited results from water permeability testing appeared to be consistent with strength and pore structure measurements.