真空脱氯法回收淡盐水中的游离氯

在离子膜法烧碱生产过程中,精制饱和盐水进入电解槽后,盐水中的NaCl约有50％被妥,出槽的淡盐水中NaCl的质量浓度一般在200g/L左右。正常生产条件下,淡盐水中游离氯的质量浓度在400mg/L以下。淡盐水在进入重饱和工序之前,必须经过脱氯工序,以除去其中的游离氯,主要作用是：防止盐水精制过程中螯合树脂和炭素发生氯中毒,减少对设备和管道的 腐蚀,节约重精制处理的费用,回收部分氯气,提高资源利用率等。     

废聚酯用品回收技术获成功

日本帝人公司研制成功从废聚酯用品回收高纯度对苯二甲酸二甲酯(DMT)和乙二醇(EG)的化学回收技术。 该技术可回收利用与其他材料混合的制成品或使用了添加剂、加工剂的制成品,得到的产品与未用过的DMT、EG产品纯度相同。 据报道,该公司目前正在改造其德山事业所的旧DMT设备,以建成年生产能力为3万吨的回收专用设备。预计这些设备可在2002年度投产。 帝人公司称,它目前主要以聚对苯二甲酸乙二醇酯)PET)瓶为回收对象,并将继续考虑利用聚酯纤维、聚酯薄膜等,公司用该技术回收的DMT等将全部自用消化。 据介绍,这项技术是将使用后的聚酯瓶粉碎、洗净,经解聚工序分离工序后,进入酯交换和重结晶工序、DMT分离工序及精制工序,精制后的DMT再经反应,得到高纯度对苯二甲酸(PTA),再生DMT纯度达99.99%,与未曾用过的纯品质量相同。 (汪硕)     

抗生素工业废水的生物流化床处理

一、概况抗生素生产中微生物发酵和化学提取、精制等工序排出的工业废水主要为(1)提取和精制过程的浓废液;(2)溶剂回收过程的浓废液;(3)设备和地面冲洗废水;(4)废冷却水;(5)染菌罐排放的废发酵液;(6)实验室废水、生活污水等。废水中有机物含量较高,直接排放入河流中,会大量消耗河水中的溶解     

信息与动态

酸洗废液浸取毒重石制备氯化钡我国冶金和金属加工行业每年有大量酸洗废液排放,该酸洗废液是冶金和金属加工行业进行钢铁表面除锈时氧化铁溶于盐酸产生的废液,其主要含有氯化亚铁和少量游离酸。用该酸洗废液代替盐酸直接浸取毒重石可制备氯化钡,不仅可以降低其生产成本,同时也为酸洗废液的综合利用提供了一条较好的出路。取毒重石粉226.1g,按n(FeCl2)/n(BaCO3)为1.2加入酸洗废液,在90℃至微沸状态下搅拌3h,趁热真空过滤,滤液经蒸发、结晶和干燥后得到氯化钡产品。用酸洗废液代替盐酸直接浸取毒重石制备氯化钡,工艺稳定,毒重石中BaCO3的…     

用钡渣制取硫酸钡

用盐酸浸取钡渣，所得的氯化钡溶液再和硫酸反庆，得到硫酸钡沉淀，母液返回去浸取钡渣。浸取钡渣的适宜条件为：浸取时间５０ｍｉｎ、ｐＨ２－３、钡渣粒度１２０目、浸取温度４０－４５℃、液固比３：１。     

采用氢氧化钠溶液循环浸出法脱除高砷阳极泥中的砷

采用氢氧化钠溶液循环浸出法处理高砷阳极泥（简称阳极泥），考察了氢氧化钠溶液与阳极泥质量比（简称液固比）等因素对限极泥中砷、锑、铅浸出率的影响。在液固比为5、氢氧化钠浓度为2．0moL／L、反应温度为70～85℃、反应时间为8h的条件下，砷浸出率可达95％以上；含砷浸出液经硫化钠沉砷后可返回浸出工序重复使用，在硫化钠与砷质量比大于3时，浸出液沉砷率维持在80％以上，同时回用浸出工序后，砷浸出率达95％以上，且铅、锑流失率较低。     

从废甲醇合成催化剂中回收铜锌

将废RK-05甲醇合成催化剂经过煅烧、浸取、精制等工序回收其中的铜和锌。经正交实验得到煅烧废催化剂的最优工艺参数为:废催化剂筛目100目,煅烧温度950℃,煅烧时间60 min。最佳浸取工艺条件为:废催化剂加入量约4 g/L,浸取温度75℃,浸取剂用量与理论用量体积比2.0~3.0,浸取剂浓度4.0 mol/L,浸取时间10min。精制工序制备CuO的最佳工艺条件为:锌粒与滤渣质量比为1.00,反应时间3 h,煅烧温度450℃,煅烧时间4 h。制备ZnO的最佳工艺条件为:煅烧温度800℃,煅烧时间60 min。回收的产品CuO纯度为99.1%,满足GB/T674—2003《化学试剂粉状氧化铜》中优级品的标准。回收的产品ZnO纯度为99.6%,满足GB/T3185—1992《氧化锌(间接法)》中一级品的标准。     

臭氧氧化结合碱液吸收法烟气脱硝的工艺研究

利用臭氧将烟气中溶解度较小的NO氧化成NO2，再结合尿素、氢氧化钠、氢氧化钙溶液吸收脱除臭氧氧化产物，重点考察了O3与NO反应的摩尔比、进口NO浓度、烟气中SO2浓度和相对湿度等工艺参数对NO氧化的影响，并探明不同的吸收液脱除臭氧氧化产物的特性。结果显示O3与NO反应的最佳摩尔比为1.02，随着进口NO浓度的增加氧化效率下降，而烟气中的SO2和相对湿度对NO氧化影响较小。通过对氢氧化钙吸收臭氧氧化产物的特性分析得出，碱液对NO的吸收率相对较小，而对NO2的吸收率达到80%以上。     

纳滤膜分离和浓缩染料的研究进展

评述了纳滤膜应用于染料分离、浓缩的理论模型，立体阻碍-细孔模型、间电荷模型、固定电荷模型、静电阻碍模型。介绍了纳滤膜在染料废水处理和染料精制浓缩中的应用研究成果。研究表明，纳滤膜用于染料废水处理和染料精制浓缩可取得理想的分离率和浓缩率。     

利用苯酐废渣生产快干型氨基醇酸烘漆

我厂年产４万ｔ苯酐装置精制工序Ｋ２０１精馏塔馏出的轻组分，主要由苯酐、苯甲酸、少量的顺酐及微量的柠糠酐组成，颜色呈淡黄色。Ｋ２０２精馏塔馏出的重组分，主要由苯酐和胶质组成，颜色呈灰黑色。两股物料混合排入废渣罐。该废渣虽然可以通过升华的方法进行回收，但回收的产物仍是苯酐和苯甲酸的混合物，不能作为规范产品销售。我们开发的苯酐废渣综合利用技术，可利用Ｋ２０１精馏塔馏出的轻组分或者两塔所排混合渣料的回收物作为原料，生产苯甲酸改性醇酸树脂，并用此树脂与氨基树脂等调合生产出氨基醇酸烘漆。该漆是我国工业涂装主…     

利用农药含钾废渣制备氯化钾

利用热解及钙盐沉淀法对农药含钾废渣进行处理,制得高纯度的KCl.通过管式炉反应器对农药含钾废渣中有机物的去除进行了研究,探讨了升温速率、热解终温、终温保持时间及空气流量对热解过程的影响,并对钙盐沉淀法除氟过程的溶液pH及m(Ca2+)∶m(F-)进行了确定.实验结果表明:当升温速率为20℃/min、热解终温为600℃、终温保持时间为90 min、空气流量为3.0m3/min时,废渣中的有机物完全分解;钙盐沉淀法除氟的最佳条件为溶液pH 8,m(Ca2+)∶m(F-)=3.0,氟离子的去除率达到98％;最终得到KCl的产率为70.6％,产品纯度为98.2％,符合国家Ⅰ级优等品标准.     

Effects of calcium hydroxide and calcium chloride addition to bentonite in iron ore pelletization.

Pyrite ash is created as waste from the roasting of pyrite ores during the production of sulphuric acid. These processes generate great amounts of pyrite ash waste that is generally land filled. This creates serious environmental pollution due to the release of acids and toxic substances. Pyrite ash waste can be utilized in the iron production industry as a blast furnace feed to process this waste and prevent environmental pollution. The essential parameters affecting the pelletization process of pyrite ash were studied using bentonite as a binder. Experiments were then carried out using bentonite and a mixture of bentonite with calcium hydroxide and calcium chloride in order to make the bentonite more effective. The metallurgical properties of pyrite ash, bentonite, calcium hydroxide, calcium chloride, a mixture of these and sintered pellets were studied using X-ray analysis. The crushing strength tests were carried out to investigate the strength of pyrite ash waste pellets. The results of these analyses showed that pyrite ash can be agglomerated to pellets and used in the iron production industry as a blast furnace feed. The crushing strength of the pellets containing calcium hydroxide and calcium chloride in addition to bentonite was better than the strength of pellets prepared using only bentonite binder.     

钡渣用于三相流化床烟气脱硫

提出了在三相流化床内用钡渣进行烟气脱硫的方法。分析了钡渣湿法脱硫原理，并进行了工艺改进实验，对两种不同溶渣方式工艺进行了静态和动态模拟实验，考察了两种方式的离子浓度和吸收容量等因素。实验表明，将渣先和水混合再用脱硫废水调整水质、脱硫塔进水pH在7．5左右时有利于系统的稳定运行。当液气比为2．88、气速为9．5m／s时，脱硫效率可以达到85％以上。这种方法可大大降低脱硫成本，实现以废治废。     

膜蒸馏过程中污染膜的清洗

针对膜蒸馏法处理石化反渗透浓水的膜面污染物进行了分析及清洗工艺优化研究。在反渗透浓水温度为73℃、渗透侧真空度为-0.093 MPa的条件下进行膜蒸馏实验,实验后期膜通量衰减迅速,脱盐率基本保持在99.5%以上,产水p H基本稳定在6.5~7.0。膜面污染物的SEM表征结果显示,膜蒸馏的膜面污染主要为碳酸钙、硅酸钙、氢氧化镁结垢污染和氯化钠、氯化钾等盐类结晶污染。实验结果表明:分别以盐酸和去离子水为清洗液静态浸泡清洗污染膜时,污染物的去除效果最好,Na OH溶液次之,草酸最差;分别采用盐酸和去离子水动态清洗污染膜,膜通量和脱盐率均能恢复到初始水平,随运行时间的延长,经去离子水清洗后膜的膜通量出现衰减。     

Recovery of yttrium from cathode ray tubes and lamps’ fluorescent powders: experimental results and economic simulation

In this paper, yttrium recovery from fluorescent powder of lamps and cathode ray tubes (CRTs) is described. The process for treating these materials includes the following: (a) acid leaching, (b) purification of the leach liquors using sodium hydroxide and sodium sulfide, (c) precipitation of yttrium using oxalic acid, and (d) calcinations of oxalates for production of yttrium oxides.Experimental results have shown that process conditions necessary to purify the solutions and recover yttrium strongly depend on composition of the leach liquor, in other words, whether the powder comes from treatment of CRTs or lamp. In the optimal experimental conditions, the recoveries of yttrium oxide are about 95%, 55%, and 65% for CRT, lamps, and CRT/lamp mixture (called MIX) powders, respectively. The lower yields obtained during treatments of MIX and lamp powders are probably due to the co-precipitation of yttrium together with other metals contained in the lamps powder only. Yttrium loss can be reduced to minimum changing the experimental conditions with respect to the case of the CRT process. In any case, the purity of final products from CRT, lamps, and MIX is greater than 95%.Moreover, the possibility to treat simultaneously both CRT and lamp powders is very important and interesting from an industrial point of view since it could be possible to run a single plant treating fluorescent powder coming from two different electronic wastes.     

氯化铵浸取法回收盐泥中的镁

以盐泥为原料,采用氯化铵浸取回收盐泥中的Mg²⁺,以浸取液和回收的氨反应制取氢氧化镁产品。考察了盐泥浆液固含量、浸取时间、物料比（氯化铵与盐泥中氢氧化镁的摩尔比）等工艺条件对Mg²⁺浸取率的影响,并以比表面积为考察指标进行正交实验,确定氢氧化镁的最佳制备条件。实验结果表明：在盐泥浆液固含量为248 g/L、浸取时间为100 min、物料比为2.3的条件下,Mg²⁺浸取率为75.0%;在n（MgCl₂）:n（NH₄Cl）=0.5、氨水浓度3 mol/L、氨水滴加速率 0.8 mL/min、反应温度 90 ℃的最佳条件下,制备的氢氧化镁的比表面积为17.87 m²/g,粒径约为3 μm。该工艺简单可行,为盐泥的综合利用提供了新的思路。     

三烯丙基异氰脲酸酯合成废渣中氯化钠的回收

采用浸取—抽滤分离—减压蒸发—结晶的方法处理三烯丙基异氰脲酸酯(TAIC)合成废渣,回收其中的氯化钠。通过单因素实验和正交实验探讨了液固比、浸取温度、搅拌时间对氯化钠回收率的影响。实验结果表明,在浸取温度为30℃、搅拌时间为30 min、液固比为15的最佳工艺条件下,氯化钠回收率为81.53%。回收氯化钠产品符合GB/T 5462—2003《工业盐》精制工业盐一级标准。采用本工艺每处理1 t TAIC合成废渣可节约费用3 064元,经济效益显著。     

利用联醇装置废催化剂生产氯化亚铜和氧化锌

叙述了用化肥厂联产甲醇装置的废催化剂生产氯化亚铜和氧化锌的原理、工艺流程和工艺条件,氯化亚铜和氧化锌的收率分别达到95%和92%.     

Recovery of copper from contaminated soil by flushing

In this work the development of a process for the recovery of copper from contaminated industrial soils is presented. Experimental tests on a standard soil contaminated with a solution of copper chloride were carried out. The metal was extracted from the contaminated soil by flushing with a 0.1 M aqueous solution of an ethylenediaminetetraacetic acid (EDTA) sodium salt. A maximum copper extraction efficiency of about 60% was observed. Copper was then separated from the extracted solution by precipitation with sodium hydroxide after addition of ferric sulfate.     

Hydrometallurgical recycling of cobalt from zinc plants residue

A large amount of hot filter cake (HFC) is annually generated in Iranian zinc plants. It contains 1% zinc, 16–30% manganese, 5–25% calcium and 1–4.5% cobalt. Usually, zinc is selectively leached by an alkaline medium and its residue is known as alkaline leached HFC (ALHFC). In the present study, the possibility of cobalt extraction from ALHFC was investigated using a creative hydrometallurgical process. At the first stage, zinc and cadmium were selectively removed with sulfuric acid. At the second stage, it was deeply focused on the possibility of selective reductive leaching of cobalt by H₂O₂ as a reductant in the presence of manganese. As results, several differences were found between the mechanism of cobalt and manganese leaching. Accordingly, cobalt leaching was more affected by acid concentration and manganese leaching was more affected by reductant concentration. Consequently, with manipulating these important parameters, it was made possible to selectively separate cobalt from manganese. Based on the obtained results, 90.9% of cobalt and only 10.04% of manganese were leached with 1% of H₂O₂. At the third stage, pregnant cobalt solution was successfully purified through a solvent extraction process with D2EHPA. Finally, cobalt hydroxide as our final product with a purity of more than 99% was precipitated from the pure pregnant solution at 70 °C.