钛酸铅-环氧树脂压电复合材料的制备

为了制备高体积填充率的钛酸铅－环氧压电复合材料，本文采用了将环氧树脂的丙酮稀溶液与钛酸铅细粉混合再抽真空除去溶剂的方法，这样有利于环氧树脂与钛酸铅进行良好的、均匀的复合，大大减少了界面气孔，所制得的复合材料钛酸铅填充率高（体积填充率达７０％），复合材料表面光滑无宏观缺陷。压电性能测定结果表明：极化条件不同，ｄ３３的值也不同，介电常数ε３３均为４３。，样品能够达到稳定极化的最佳ｇ３３的值为：２３．１×１０－３Ｖ·ｍ·Ｎ－１。

环江某铅锌矿中黄铁矿的浮选试验研究

针对广西环江某铅锌多金属硫化矿铅锌浮选尾矿中黄铁矿的特殊性,采用新型捕收剂C08与新型活化剂F09组合使用,解决了硫酸等活化剂不能活化的难题,可获得硫精矿S品位48.50%、硫作业S回收率94.71%的良好选别指标。

铅屏蔽环在钢丝绳上的新颖固定工艺

文章分析了采用多种工艺方法来解决铅屏蔽环与钢丝绳的固定问题。通过对比,择优筛选出压合法工艺。对该工艺所涉及到的设计、工艺等问题,进行了综合性的阐述、计算、和论证。该工艺具有一定创新性。

不同构造参数对加劲环铅芯钢管阻尼器的性能影响

文中对铅芯钢管阻尼器的钢管结构采用了加劲环的处理方法,研究不同的构造参数对阻尼器的耗能能力的影响情况,并通过建立ABAQUS有限元模型的方法,采用位移控制的低周往复加载制度,模拟得到不同构造参数下加劲环铅芯钢管阻尼器的滞回曲线、等效阻尼比的数据。研究结果表明,采用加劲环铅芯钢管阻尼器结构形式,能够有效避免阻尼器发生较大的弯曲破坏;加劲环铅芯钢管阻尼器的高径比,厚径比以及加劲环宽厚比的参数选取,对阻尼器的初始刚度和承载能力影响是非常明显的。因此,合理选取构造参数对优化结构设计具有重要意义。

一种温控器无铅锡环用高性能助焊剂的研制

针对现有温控器焊接用强酸液体助焊剂残留过多、腐蚀严重和温控器可靠性低的问题,研制了以己二酸、环己胺盐酸盐和有机卤盐活化剂M为活性剂,松香、聚乙二醇和十八酸为载体,二溴丁烯二醇为表面活性剂的温控器无铅锡环用助焊剂。结果表明该助焊剂能在较宽的温度范围内持续提供活性,助焊效果好,焊缝抗腐蚀性增强,漏气率低,可靠性大大提高。

管链输送机在铅冶炼行业中的应用

华东某再生铅冶炼厂利用侧吹炉处理废旧铅酸蓄电池过程中,侧吹熔炼车间产生的环集烟气经布袋除尘后送往脱硫系统,除尘器捕集的铅环集烟尘采用管链输送机输送到原料库的烟尘仓并返回侧吹炉系统。管链输送机的结构简单紧凑,可以水平、垂直、弯曲和三维布置,具有广泛的应用前景。

Environmental risk assessment on slag and iron-rich matte produced from reducing-matting smelting of lead-bearing wastes and iron-rich wastes

A new process for utilization of hazardous lead-bearing wastes and iron-rich wastes by reducing-matting smelting has been developed.The slag（SG） and the iron-rich matte（IRM） are the main by-products from reducing-matting smelting of lead-bearing wastes and iron-rich wastes.The environmental risk of heavy metals（Cd,Zn,Pb and As） in the main by-products versus the charging material for reducing-matting smelting（CM） has been systematically assessed using leaching toxicity test,the three-stage sequential extraction procedure of European Community Bureau of Reference（BCR） and Hakanson Potential Ecological Risk Index Method（PERI）.The results demonstrate that the ecological risk level of heavy metals for SG and IRM is significantly reduced after the reducing-matting smelting process compared with that for CM.

Adsorption and Desorption Characteristics of Cadmium and Lead in Typical Paddy Soils of Jiangxi Province and Its Environmental Risk Assessment

[Objective] This study aimed to investigate the adsorption and desorption characteristics of cadmium and lead in typical paddy soils of Jiangxi Province. [Method] Gleyed paddy soil and waterloggogenic paddy soil were collected from Jiangxi Province and used as experimental materials to investigate single and com- petitive adsorption and desorption behaviors of cadmium and lead by batch equilib- rium method. The environmental risk of the presence of cadmium and lead in paddy soils was assessed using distribution coefficients. [Result] Under equal ratio condi- tions, the adsorption capacity of lead by two types of paddy soils was higher than that of cadmium, and the adsorption rate in waterloggogenic paddy soil was higher than that in gleyed paddy soil. The desorption capacity of cadmium by two types of paddy soils was higher than that of lead, and the desorption rate in gleyed paddy soil was higher than that in waterloggogenic paddy soil. Under competitive condi- tions, the adsorption capacity of cadmium and lead by paddy soils was significantly reduced compared with single ion system, while the desorption rate was remarkably improved. The potential environmental risk of cadmium contamination was greater than that of lead in paddy soils. Moreover, environmental risks of cadmium and lead were reduced with the increase of pH, which increased significantly under the coex- istence state. [Conclusion] In the coexistence of cadmium and lead, cadmium con- tamination should be controlled and avoided compared with lead contamination in paddy soils.

Lead electrodeposition from alkaline solutions containing xylitol

The electrodeposition of lead in alkaline solutions containing xylitol （1, 2, 3, 4, 5-pentahydroxypentane） was studied. The lead electrodeposition and the chemical stability of xylitol in alkaline solutions were investigated by cyclic voltammetry. Apparent activation energy, apparent transfer coefficient and exchange current density were obtained by linear sweep voltammetry. Initial stages of lead electrocrystallization were determined by chronoamperometry. Voltammograms of a AISI 316 stainless steel electrode in xylitol solution exhibit no current in the potential range of-1.3 V to 0.75 V （vs Hg/HgO）, implying that xylitol is stable to oxidation and reduction. The apparent activation energy, apparent transfer coefficient and exchange current density were calculated to be 35.15 kJ/mol, 1.56 and 9.65x10^-5 A/m^2. Analysis of the chronoamperometric responses implies three-dimensional growth of nuclei, with the type of nucleation depending on overpotential.

Electrochemical behavior of galena and jamesonite flotation in high alkaline pulp

In order to effectively separate galena and jamesonite and improve the recovery during the mixing flotation, the interaction mechanisms between the minerals and the collector of diethyl dithiocarbamate （DDTC） were investigated. Single mineral flotation test was organized to research the effect of pulp pH value on the flotation behavior of galena and jamesonite. Electrochemistry property of the interaction of these two minerals with DDTC was investigated by cyclic voltammetry and Tafel tests. Flotation test shows that the recovery of jamesonite in high alkaline pulp is strongly depressed by lime （Ca（OH）2）. The cyclic voltammetry and Tafel tests results show that the interaction between galena and DDTC is an electrochemical process. High pH value has little influence on the interaction between galena and DDTC, while it has great effect on jamesonite due to self-oxidation and specific adsorption of OH^- and CaOH^＋ on jamesonite surface. Non-electroactive hydroxyl compound and low-electroconductive calcium compounds cover the surface of jamesonite, which impedes electron transfer and DDTC adsorption, thus leads to very low floatability of jamesonite.

Spontaneous separation of Pb from PbSO_(4)-coprecipitated jarosite using freeze-thaw cycling with thiourea

To separate Pb from PbSO_(4)-coprecipitated jarosite,a novel thiourea-induced freeze-thaw cycling(T-FTC)process was investigated.Results show that distributed PbSO_(4)particles are pressed and aggregated around the jarosite particles by T-FTC.Under the freezing-concentration effect of T-FTC,the reaction between PbSO_(4)and thiourea is also promoted,forming lead thiourea sulfate(Pb-tu).As the cycles of T-FTC increase,PbSO_(4)around jarosite disappears for the reaction of forming Pb-tu.After 12 cycles of T-FTC,a spontaneous separation is observed between Pb-tu and jarosite,i.e.,Pb-tu is separated into the upper layer while jarosite-rich phases remain in the lower layer.Due to this spontaneous separation,leaching toxicity of the jarosite coprecipitates is reduced by 73.7%.These results suggest that T-FTC process can achieve the separation of Pb from PbSO_(4)-coprecipitated jarosite and is a promising approach for removing and recovering metals from iron-rich jarosite residues.

Tracing environmental lead sources on the Ao mountain of China using lead isotopic composition and biomonitoring

Atmospheric lead （Pb） and other trace metals can transport over long distance and deposit on remote alpine ecosystems. In this work, the soil profiles, litter and dominant mosses along a large altitude were collected on Ao Mountain, Central China, to obtain the spatial distributions of Pb in these materials, decipher the possible factors controlling the distribution, and quantitatively distinguish the natural versus anthropogenic sources of Pb through the Pb isotopic tracing and biomonitoring. The results show that soil Pb concentrations （mg/kg） decreased significantly with depth, and they were markedly higher in the 0 （42.6 ＋ 2.7） and A （36.4 ＋ 2.2） horizons than in the litter （7.20 ~ 1.9） and mosses （28.o ~ 3-9）- The Pb enrichment in the surface soils （0 and A horizons）, litter and mosses existed in the relatively high altitudes, which was attributed to the influences from atmospheric wet deposition, plants, soil Dhvsicochemical DroDerties and human activitv. ThePb isotopic ratios identified the Pb sources as originating mainly from Chinese coal combustion, mining and smelting. Atmospheric Pb from southeastern, southwestern and northwestern regions could be deposited in the alpine ecosystem by long distance atmospheric transport. The anthropogenic Pb reached over 50% in the 0 and A horizons, and over 70% in the litter and mosses, which corresponded to the concentrations of 26.9, 17.7, 5.92 and 21.2 mg/kg, respectively. The results indicate that the mutual effects of climate and regional human activity could increase the Pb accumulation in remote alpine ecosystems.

Environmental contamination and health hazard of lead and cadmium around Chatian mercury mining deposit in western Hunan Province,China

A field survey concerning lead and cadmium pollution in environment mediums and hair samples around the Chatian mercury mining deposit in western Hunan Province,China,was conducted to preliminarily evaluate their health hazard to local inhabitants.The results show that mining wastes,especially tailing,contain high cadmium level with the maximum of 79.92μg/g. High levels of lead and cadmium are accumulated in surface water and paddy soil,respectively,and both metals pollution occurs in brown rice.The average daily intake dose(ADD)of lead for local adults via three routes reaches up to 7.7μg/(kg·d),exceeding the provision tolerable daily intake by JECFA of 3.5μg/(kg·d),and drinking water exposure route contributes the highest daily intake.As an indicator for heavy metal exposure,the hair of local population contains Pb(5.06±3.02)μg/g.The average daily intake dose of cadmium for adults is 0.119μg/(kg·d).More attention must be paid on health risk from lead pollution compared with cadmium.

Trace Metals （Cu, Pb, Zn, Mn, Mo, As） Analysis as a Base for Environmental Studies in Argentina

In Argentina, at Central Andes Eastside, Cumbres Calchaquies, Aconquija Range and Ambato Block constitute a mountain chain that erects about 5,000 masl. Its geological story reveals morphotectonic and magmatic processes are similar to the Pampean Ranges at which they belong to, giving origin to mineralized areas. Geochemical concentrations of trace metals （Cu, Pb, Zn, Mn, Mo, As） in stream sediments are related to the geology and mineral manifestations of the area. Geochemical high average concentration of Cu, Pb and Mo are observed in all ranges. It highlights the presence of As in Cumbres Calchaquies-Aconquija Range and Zn, Mn in the mountains of Aconquija Range-Ambato Block. It was determined that Cu-Zn-Mn complex is adsorbed or precipitated most frequently by Mn oxides. Complex Pb-Zn, Mn-As, Mo-As and Pb-Mo are absorbed by other agents （clay; oxides of Mn, Fe, AI; organic matter）.

Research of Adsorption and Desorption Characteristics of Cu and Pb in Typical Paddy Soils in Jiangxi Province

[Objective] This study was conducted to investigate the adsorption and desorption characteristics of Cu and Pb in typical paddy soils in Jiangxi Province. [Method] Two kinds of typical paddy soils （Gley type, Waterloggogenic type） in Jiangxi Province were chosen as test materials. The single and competitive adsorption behaviors of Cu and Pb in paddy soils were investigated with batch equilibrium method, and the environmental risk under coexistence of Cu and Pb in these soils was estimated with distribution coefficient. The results showed that under equal proportion, the adsorption affinity of Pb was greater than that of Cu in the two paddy soils, and the adsorption capacities in waterloggogenic paddy soil （WPS） were significantly higher than those in gley paddy soil （GTPS）, but the desorption capacities of Cu were greater than those of Pb in the two paddy soils, and the desorption capacities in GTPS were significantly higher than those in the WPS. The adsorption capacities of Cu and Pb ions under competitive condition were obviously lower than those in single system, while the desorption rates significantly increased. The potential environmental risk of Cu pollution was greater than that of Pb in paddy soils, and their environmental risk decreased with the increase of pH, but increased significantly under coexistence of lead and copper. [Conclusion] This research suggests that when Cu and Pb ions coexist in the paddy soils, compared with lead pollution, we should pay attention to the pollution of Cu.

Cyclic metallurgical process for extracting V and Cr from vanadium slag: Part Ⅱ. Separation and recovery of Cr from vanadium precipitated solution

Cyclic metallurgical process for separation and recovery of Cr from vanadium precipitated solution by precipitation with PbCO_(3)and leaching with Na_(2)CO_(3)was investigated.The concentration of Cr residue in the solution decreases from 2.360 to 0.001 g/L by adding PbCO_(3)into vanadium precipitated solution according to Pb/Cr molar ratio of 2.5,adjusting the pH to 3.0 and stirring for 180 min at 30℃.Then,the precipitates were leached with hot Na_(2)CO_(3)solution to obtain leaching solution containing Na_(2)CrO_(4)and leaching residue containing PbCO_(3).The leaching efficiency of Cr reaches 96.43%by adding the precipitates into 0.5 mol/L Na_(2)CO_(3)solution with the mass ratio of liquid to solid(L/S)of 10:1 mL/g and stirring for 60 min under pH 9.5 at 70℃.After filtration,leaching residue is reused in Cr precipitation and leaching solution is used to circularly leach the Cr precipitates until Na_(2)CrO_(4)approaches the saturation.Finally,the product of Na_(2)CrO_(4)·4H_(2)O is obtained by evaporation and crystallization of leaching solution.

对PYD圆锥破碎机轧臼壁与调整环铅锌合金的改进

PYD1200圆锥破碎机的轧臼壁第一次松动后，用配比1：1的铅锌合金，重新浇入轧臼壁与调整环之间，效果不佳。使用沙浆混凝土代替铅锌合金浇入轧臼壁与调整环之间作粘附物，取得了较好的使用效果。

Development of the zinc-air power battery on electric bicycles in China

Electric bicycles powered by lead-acid batteries have developed very fast for several years in China. Because the inconvenience caused by the service performance and the inconsistency to the environmental protection policy of the lead-acid battery, the zinc-air power battery was proposed to solve the problem in this paper. The advantage and the feasibility of developing zinc-air power batteries in China have been illustrated in the paper. And, it is represented that development of electric bicycles powered by the zinc-air power battery also can accelerate this kind of battery's development in other electric vehicles, which is favorable to economic development and environmental protection.

Bioremoval of Aquatic Environment Lead by Immobilized Cells of Enterobacter spp.

This work aimed to investigate the biosorption of lead by free and immobilized bacterial cell. Twenty four samples were collected from the wastewater of batteries factory in AL-Waziria district for the period from June to Sept. 2004, three species of bacteria have been isolated from this wastewater： Enterobacter agglomerans, E. gergoviae, and E. sakazakii. The results revealed a high variation in the ability of these bacteria for lead biosorption, the bacteria E. agglomerans （ES） was the most efficient compared to the other bacterial species. A laboratory plant with continuous flow system was designed for lead ions removal from standards aqueous solutions, as the cells were immobilized using： white sand, charcoal, agar and calcium alginate. However, the cells immobilized to calcium alginate were the most efficient in removal of lead ions （98%）. Present study also determined the optimal conditions for the biosorptJon of lead ions which were temperature 40℃ and pH 4 with one hour contiguity between the immobilized bacteria and solution. Different washing solutions were used fo~： recovering the lead ions that have been biosorbed on the bacterial walls, 0.1 M EDTA was the most efficient. Preferential biosorption by E. agglomerans （E5） to copper and cadmium was determined, result showed that the order of this preferential capability was： Cu 〉 Pb 〉 Cd. No significant differences were found in the biosorption of lead ions by alive and dead E. agglomerans （E5）. The designed lab plant containing bacterial cells binding on calcium alginate was able to uptake all lead ions from all samples of industrial wastewater of batteries factory.

Behavior, distribution and environmental influence of arsenic in a typical lead smelter

A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arsenic in selected samples were evaluated. Arsenic contents in all input and output samples vary from 0.11% in raw lead to 6.66% in collected dust-2. More arsenic is volatilized in blast furnace and fuming furnace(73.02% of arsenic input) than bottom blowing furnace(10.29% of arsenic input).There are 78.97%, 13.69%, 7.31% of total arsenic distributed in intermediate materials, stockpiled materials and unorganized emissions, respectively. Matte slag-2, collected dust-1 and secondary zinc oxide are hazardous based on the arsenic concentrations of toxicity characteristic leaching procedure. According to risk assessment code(RAC) guideline, arsenic in collected dust-1 poses a very serious risk to the surrounding environment, arsenic in speiss, matte slag-2, water-quenched slag and secondary zinc oxide show low risk, while arsenic in matte slag-1, collected dust-2 and post dust has no risk to the environment.