基于磷酸铁锂提锂渣的电池级磷酸铁制备工艺研究

目前在磷酸铁锂电池正极材料回收时往往仅回收其中经济价值高的锂元素，而产生的提锂渣中大量磷酸铁因杂质中的铝元素脱除困难导致无法回收利用，造成了巨大的资源浪费。为此，提出了一种使用硝酸浸提磷酸铁的方法。首先在浸出液中加入甲醇电解还原浸出液中的铁离子，再向还原液中加入氢氟酸作为沉淀剂脱除酸浸液中的铝离子，脱铝后的酸浸液用过氧化氢将亚铁离子氧化为铁离子，再加入甲醛并加热沉淀出电池级磷酸铁。研究结果表明：在浸取温度70℃、硝酸浓度5 mol/L、酸浸40 min的条件下，Fe的浸出率为92.7%;经电解还原亚铁后脱铝制备出了Al质量分数仅为72 mg/kg的磷酸铁，满足HG/T 4701-2021《电池用磷酸铁》的Ⅱ型标准。该方法为磷酸铁锂提锂渣的回收利用提供了一条新思路。     

提高肌醇收率的研究(Ⅰ)

降低脱脂糠的油脂及淀粉含量,用氨水作菲汀酸浸液的中和沉淀剂,用碳酸钙与氢氧化钙的混合粉末作中和除盐剂,制取六碱土金属植酸盐,用离子交换法对肌醇溶液进行精制,可提高肌醇的收率。     

一种高镁磷矿中氧化镁的快速测定方法

本发明是一种高镁磷矿中氧化镁的快速测定方法,其步骤如下:将样品置于容器中,加入酸加热分解,所述的酸为硝酸溶液;加入沉淀剂,加热煮沸,取下冷却,所述的沉淀剂为钼酸铵溶液;将溶液和沉淀一起定容到容量瓶中,摇匀;干过滤,吸取一定量的溶液,加入掩蔽剂三乙醇胺溶液,用EDTA分别滴定钙的含量和钙镁合量;记录滴定溶液消耗的体积计算得到氧化镁的含量。本发明加入沉淀剂使得磷酸根与钙镁分离,而且沉淀和溶液一起定容到容量瓶中,免去了过滤     

以硫铁矿烧渣为原料氯酸钠氧化法制备PFS的研究

在硫铁矿烧渣与硫酸反应所得的酸浸液中加入一定量的七水硫酸亚铁和氯酸钠 ,制备得到聚合硫酸铁 (PFS)。研究了氯酸钠氧化法制备 PFS的影响因素。该方法工艺简单 ,反应时间短 ,无催化剂 ,并具有对环境友好和一定的经济效益。     

炼钙还原渣和煤矸石制备聚合氯化铝的研究

采用煅烧后的煤矸石酸浸液与炼钙还原渣反应制备聚合氯化铝（PAC）。考察了炼钙还原渣投加量、反应时间和反应温度对PAC性能的影响,并采用红外、热重分析对其进行表征,结果表明：向酸浸液中加入一定量炼钙还原渣,在95 ℃下反应4 h,便可得到三氧化二铝质量分数为28.1%、盐基度为68.9%的固体PAC,符合GB/T 22627—2014《水处理剂 聚氯化铝》的要求。     

炼铜烟灰批式滴加酸浸锌与两步氧化除铁工艺

采用炼铜烟灰制取硫酸锌,研究了批式滴加酸浸取锌和两段除铁工艺．实验结果表明：用批式滴加法浸取,锌浸取率≥98％、铜浸出率≥96％,铁浸取率可控制在0．02％以下．其工艺条件为：液固质量比3∶1,温度80～90℃,酸浸液中硫酸加入量39g／L,滴酸时间1．5h,浸取时间2h．采用先通氧（或鼓空气）氧化,再加过氧化氢深度氧化除铁工艺,溶液最终铁含量≤0．01g／L．制得的硫酸锌可用于电解．     

优化PTA氧化单元催化剂消耗

介绍PTA氧化单元催化剂流程,针对催化剂存在消耗高、成本高问题进行了分析。从过滤系统的喷淋酸量、喷嘴有效面积、过滤机转速、离心机的沉淀剂、CTA(粗对苯二甲酸)品质等方面,分析了氧化单元催化剂消耗高的影响因素,并提出相应措施,进而对系统进行简单优化处理。     

液相沉淀法制备草酸钴粉体的研究

草酸钴是制备钴粉或者氧化钴的主要原料.以硫酸钴、草酸铵、革酸为原料,采用液相沉淀法制备草酸钴粉体.研究了沉淀剂、加料方式、反应温度、反应物浓度等对制备草酸钴粉体粒度和产率的影响.研究结果表明:用草酸铵作沉淀剂,反应温度为50℃时,将草酸铵固体迅速加入到硫酸钴溶液中(固-液加料方式),可得到粒度均匀、粒径为1.1μm的超细草酸钴;而采用草酸铵溶液加入到硫酸钴溶液中(液-液加料方式),草酸钴产率可高达99.6%,但粒度较大.     

强化酸浸提金及除砷和铁的试验研究

对含硫砷难选矿烧渣酸浸氰化提金进行了试验。通过稀酸浸出除砷正交试验,得出酸浸液种类是影响除砷效果最关键的因素,最优工艺参数是酸浸时间为60 min,固液比约1∶2,酸浸温度为20℃,酸浸液种类为5%硫酸。通过强化酸浸提高金浸出率正交试验,得出酸浸温度是影响金浸出率最关键的因素,最优工艺参数是:硫酸浓度65%,矿酸比1∶2,酸浸温度95℃,酸浸时间4 h。通过强化酸浸液除铁探索性试验,有效地提取了酸浸液中的铁,得出单程试验FeSO4·7H2O结晶的收率达到83.01%,其中砷含量为0.03%,经一次洗涤后可降到0.006%。     

氯硝柳胺生产废水的预处理研究

针对氯硝柳胺生产废水中高COD及超高浓度总磷,采用酸析、铁炭微电解、Fenton氧化和钙法沉淀处理技术进行预处理。研究表明,通过对除磷沉淀剂的选择、p H以及加药量等关键因素的控制,可做到废水经过预处理后,COD去除率达88%,除磷率达99.8%,有效降低了废水中COD和总磷浓度,出水达到生化处理进水要求。     

黄磷生产中火灾事故的预防

通过对生产规模2500t／a黄磷生产厂生产实践的分析，提出发生事故的几种主要原因，如磷及磷泥的自燃、尾气爆炸及CO中毒、磷渣的排放和磷铁回收等，总结了处理和防范事故的一些实际经验，对小型黄磷生产厂具有一定的参考作用。     

反硝化聚磷菌在污水处理中的应用

综合国内外反硝化除磷技术的最新研究,着重分析反硝化聚磷菌的脱氮除磷机理和对反硝化除磷工艺有较大影响的各种因素,介绍反硝化聚磷菌在污水处理中的应用及目前反硝化除磷技术在工艺上的研究进展。     

A simple equation for calculating the residual effect of phosphorus fertilizers

A simple equation to calculate the residual effect of fertilizer phosphorus is derived from a model distinguishing only two soil phosphorus pools. With time intervals of one year the model calculates the phosphorus transfers between the pools, the uptake of phosphorus by the crop and the resulting pool sizes. Most input data required to operate the model can be obtained from ordinary one-season phosphorus fertilizer trials.For easily soluble phosphorus fertilizers the residual effect can also be calculated with a formula: Rt = (0.8 – R1)^t-1* R1 where Rt and R1 are the recovery fractions in year t and year 1, respectively. During the first five years after fertilizer application the residual effects, as calculated with the equation, are almost equal to those obtained with the model.     

Denitrification and Dephosphatation by Anaerobic/Anoxic Sequencing Batch Reactor

Removal of denitrifying phosphorus was verified in a laboratory anaerobic/anoxic sequencing batch reactor (A/A SBR). The results obtained demonstrated that the anaerobic/anoxic strategy can enrich the growth of denitrifying phosphorus removing bacteria (DPB) and take up phosphate under anoxic condition by using nitrate as the electron acceptor. The phosphorus removal efficiency was higher than 90% and the effluent phosphate concentration was lower than lmg·L-1 after the A/A SBR was operated in a steady-state. When the chemical oxygen demand(COD) of influent was lower than 180mg·L-1, the more COD in the influent was, the higher efficiency of phosphorus removal could be attained under anoxic condition. However, simultaneous presence of carbon and nitrate would be detrimental to denitrifying phosphorus removal. Result of influence of sludge retention time (SRT) on denitrifying phosphorus removal suggested that the decrease of SRT caused a washout of DPB and consequently the enhanced biological phosphorus     

厌氧／缺氧SBR反硝化除磷过程的研究

Removal of denitrifying phosphorus was verified in a laboratory anaerobic/anoxic sequencing batch reactor (A/A SBR). The results obtained demonstrated that the anaerobic/anoxic strategy can enrich the growth of denitrifying phosphorus removing bacteria (DPB) and take up phosphate under anoxic condition by using nitrate as the electron acceptor. The phosphorus removal efficiency was higher than 90% and the effluent phosphate concentration was lower than 1mg·L^-1 after the A/A SBR was operated in a steady-state. When the chemical oxygen demand(COD) of influent was lower than 180mg·L^-1, the more COD in the influent was, the higher efficiency of phosphorus removal could be attained under anoxic condition. However, simultaneous presence of carbon and nitrate would be detrimental to denitrifying phosphorus removal. Result of influence of sludge retention time (SRT) on denitrifying phosphorus removal suggested that the decrease of SRT caused a washout of DPB and consequently the enhanced biological phosphorus removal decreased with 8 days SRT. When the SRT was restored to 16 days, however, the efficiency of phosphorus removal was higher than 90%.     

黄磷精制工程化示范装置设计实践

概述了黄磷精制脱砷系统的工艺流程、主要设备及在工程化设计中遇到的问题及设计采取的技术措施。通过实践证明,该装置工艺流程简单,设计合理,运行可靠,脱砷效果好,产品技术指标达到预期要求。     

Sorption of labelled phosphate by a Vertisol and an Alfisol of the semi-arid zone of India

Information on phosphate sorption properties of Vertisols is scarce, but can help to explain the different responses of crops to fertilizer P on Vertisols, as compared with Alfisols.Adsorption isotherms for total adsorbed phosphate and isotopically exchangeable phosphate were measured for typical examples of a Vertisol and an Alfisol, occurring in close proximity at the ICRISAT centre. For each soil, the relationships of exchangeable P and total adsorbed P with phosphate solution concentration were described well by the Freundlich isotherm. Neither of the soils adsorbed significant amounts of P in a non-exchangeable form. The Vertisol had a higher capacity and buffer power for phosphate sorption, implying a lower response to fertilizer P. However, all adsorbed P remained in forms labile to³²P, equilibrated for 22 h, so that for equal amounts of CaCl₂ extractable P there was more labile P in the Vertisol. In the absence of added P, the data suggested that the Vertisol maintained a greater level of dissolved and labile P. These observations are in accord with the results of field experiments, where larger applications of P may be required in Vertisols, compared with Alfisols, to achieve the same yield response, but that P is more freely available to crops grown in Vertisols than is suggested by chemical extraction methods for available P.     

用磷表快速测定磷石膏中水溶磷和非水溶磷

用磷表分析法代替磷钼酸喹啉容量法测定磷石膏中的水溶磷和非水溶磷,分析方法简单,经与传统容量法对照,结果准确、可靠,降低了分析成本,能满足生产控制分析需求。     

Estimates of soil phosphorus for different soil series

Over a range of soil series, the responses to applied P were measured with Swedish turnips and potatoes in field experiments and with oats in a pot experiment. Phosphorus was extracted from soil samples, taken before the experiments were started, by acetic acid, Morgan's, bicarbonate, resin and lactate methods. The relationships between the amounts of soil P extracted and the responses to applied P showed that curved models, using reciprocals or logarithms of soil P, were generally superior to linear and quadratic models especially for the field experiment data. Including loss-on-ignition in the model significantly improved the relationships for some soil series.Reciprocal and logarithmic models were used to determine the ranges for classifying soil P into three classes and to calculate responses to soil P at each site. For the experiments with Swedish turnips, soil P and calculated responses were allocated to three classes and compared with the corresponding classification of the actual field responses. Using different ranges of critical values for classifying soil P for a specific series is shown to be at least as important as using the best method of extraction. The results illustrate how the reliability of a three-class system for predicting the P status of these acid, Scottish soils can be increased by using different class intervals for soil P for different series.     

三氯化磷生产装置的技术改造及运行总结

介绍了三氯化磷产品的运行状况.采用黄磷与氯气直接氯化法生产三氯化磷,对不合理工艺过程进行技术改造,总结了日常生产的控制措施.