Synergistic extraction of zinc from ammoniacal solutions using β-diketone mixed with CYANEX923 or LIX84I

The extraction behaviors of zinc from ammoniacal solutions were investigated using β-diketone （HA） and their mixtures with CYANEX923 or LIX84I. The effects of pH, total ammonia concentration, extractant concentration, anion species and temperature on zinc extraction were examined. The synergistic mechanism was discussed with regard to the structure of extractant and the extracted zinc complexes. It is found that the increase of total ammonia concentration and pH inhibits zinc extraction for all extraction systems due to the formation of zinc ammine complexes in aqueous phase. This effect of HA with CYANEX923 is evidently smaller than that of HA with LIX84I or HA alone system. Effect of anion species on the zinc extraction by HA with CYANEX923 can be neglected, but this effect of HA alone and the mixture of HA with LIX84I decreases in the order of （NH4）2SO4 〉 NH4NO3 〉 NH4Cl.

Recovery of copper from simulated ammoniacal spent etchant using sterically hindered beta-diketone

The solvent extraction of copper from simulated ammoniacal spent etchant with 1-（4＇-dodecyl）-phenyl-3-tertiary butyl-1,3-octadione（HR） was studied,and a model of extraction isotherm was proposed and verified with equilibrium extraction constant.The influence of equilibration time,extractant concentration and phase ratio on the extraction of copper was studied at（298±0.5） K.For the spent etching solutions containing 112.98 g/L Cu,6 mol/L NH3 and 1 mol/L NH4＋,the optimal solvent extraction condition of copper was obtained in one-stage solvent extraction at phase ratio of 5：4 with 40% HR in sulphonated kerosene for 5 min.The copper concentration in the raffinate decreased to 63.24 g/L and raffinate can be favorably recycled to the etching solution.The stripping studies were carried out with the simulated copper spent electrolyte containing 30 g/L Cu and 180 g/L H2SO4.The stripping ratio is 98.27% from the loaded organic phase after one-stage stripping at phase ratio of 1：2 at（298±0.5） K.

Treatment of copper-rich gold ore by cyanide leaching, ammonia pretreatment and ammoniacal cyanide leaching

The treatment of a copper sulphide-bearing gold ore by direct cyanide leaching, ammonia pretreatment and ammoniacal cyanide leaching was investigated. Dissolution behaviour of gold and copper in these leaching systems was demonstrated. Severe interference by the copper containing sulphides with cyanide leaching of gold is observed at p（NaCN）〈5 g/L. This is consistent with speciation calculations. Ammonia pretreatment is shown to readily eliminate the copper interference, allowing almost complete extraction of gold with concomitantly low reagent consumption in subsequent cyanide leaching. In ammoniacal cyanide system, Box-Behnken experimental design shows the main and interaction effects of NH3, NaCN and Pb（NO3）2. The concentrations of NH3 and NaCN are statistically confirmed to be significant factors affecting extraction of gold while the effect of Pb（NO3）2 is limited. Increasing the concentration of NH3 improves the selectivity and extent of gold extraction and reduces the cyanide consumption. The contribution of reagent interactions to gold extraction is statistically insignificant. These findings highlight that ammonia pretreatment and ammonia-cyanide leaching are promising approaches for the treatment of gold ores with high copper sulphide content.

Deep Purification of Zinc Ammoniacal Leaching Solution by Cementation with Zinc Dust

Deep purification of zinc ammoniacal leaching solution by cementation using zinc dust was studied.The effects of relative amount of metallic impurities,dosage of zinc dust,purification time,temperature,pH value and total ammonia concentration in the solution on the purification of the solution were investigated.The results indicate that total ammonia concentration in the solution had no effect on the purification,but relative amount of metallic impurities,dosage of zinc dust,purification time,temperature and pH value of the solution were the main factors influencing the purification.Keeping appropriate molar ratio of copper to cadmium or nickel to cadmium was beneficial to the cementation of cadmium.Nevertheless,the presence of cobalt went against the cementation of cadmium and cobalt.All metallic impurities could be decreased to acceptable levels under the optimized conditions of 2 g/L of zinc dust dosage,1 h of purification time,35℃,pH value 9.03 of zinc ammoniacal leaching solution.The deeply purified zinc ammoniacal solution obtained by one-stage purification meets the requirements of zinc electrowinning.

Solvent extraction of copper and ammonia from ammoniacal solutions using sterically hindered β-diketone

Extraction of copper and ammonia from Cu2+-NH3-Cl--H2O solution using laboratorialy synthesized sterically hindered β-diketone(4,4-dimethyl-1-(4-dodecylphenyl)-1,3-pentanedione) was studied.The effects of the copper concentration,the total ammonia concentration,the initial pH in the aqueous phase,the phase ratio,and the temperature on copper extraction ratio and ammonia extraction in loaded organic phase were investigated using this sterically hindered β-diketone.Under the conditions of temperature 25℃,contact time of two phases 30 min,phase ratio 1-1,concentration of copper 3 g/L,concentration of total ammonia 3 mol/L,aqueous pH 8.43,and the concentration of β-diketone in organic phase 20%(volume fraction),ammonia in aqueous phase is much lower to be extracted by organic phase(just 14.5 mg/L),while the extraction rate of copper is 95.09%.

Treatment of a Polysulphide Ore by Ammoniacal Thiosulfate Solutions and Ion Flotation for Gold Recovery

Ammoniacal thiosulfate solutions with cupric ions have proved to be more successful than cyanidation in handling complex ores like carbonaceous and cuprous minerals. That＇s why cyanidation and ammoniacal thiosulfate leaching was performed at 33% of solids concentration in order to compare the efficiency of both techniques. Cyanidation delivered a gold recovery of 80.6% at 24 hours of agitation, whereas ammoniacal thiosulfate leaching achieved an 80.9% of gold recovery in only one hour of agitation. Then, the ammoniacal thiosulfate solutions obtained were submitted to five gold recovery techniques （carbon adsorption, cementation, adsorption on carbon impregnated with metallic copper, ion flotation and electrolysis） in order to determine which one of them was the most effective technique. Ion flotation proved to be the best technique due to its gold recovery of 84%. In addition, this technique only required trioctyl methyl ammonium chloride （Aliquat） and FloMin F-121 in a 0.1% concentration inside the solution. The small amounts of the flotation reagents allow the flotation concentrate to be treated by electrolysis. It was performed with 1.5 V during three hours and the resulting gold recovery was 82% in the cathode zone.

Experimental Research on Intratumoral Injection of Sal Ammoniac Extract in the Treatment of Mouse Liver Cancer

Objective:To study the effect of sal ammoniac extract on the treatment of liver cancer and analyze its possibility of replacing absolute ethanol.Methods:Sixty Kunming mice(5-6 weeks old,18-22g in weight,male and female in half)were selected and inoculated with 0.1 ml of 1:4 ascitic diluent from mouse liver cancer H22 under the axilla of the right limb.After tumor formation,they were randomly divided into 3 groups with 20 mice in each group.Normal saline(NS),sal ammoniac extract(N),and absolute ethanol(E)were injected into the tumor once a day for four times.The death,tumor weight,tumor inhibition rate,lactate dehydrogenase(LDH),and succinate dehydrogenase(SDH)expression of the mice in each group were analyzed.Results:In the course of treatment,3 mice died in the normal saline group,2 mice died in the sal ammoniac treatment group,and 7 mice died in the absolute ethanol group.The tumor weight of the normal saline group,sal ammoniac treatment group,and absolute ethanol group were 1.880.26,1.41±0.49,and 1.51±0.46,respectively.The tumor inhibition rates were 0%,31.0%,and 21.6%,respectively.Comparing the sal ammoniac treatment group and the normal saline group,t=3.5133,p=0.0013;comparing the absolute ethanol group and the normal saline group,t=2.7926,p=0.0093.The expression of LDH was 81±10,51±11,and 32±9 in the normal saline group,sal ammoniac treatment group,and absolute ethanol group,respectively,while the expression of SDH was 80±10,5110,and 51±12 in the normal saline group,sal ammoniac treatment group,and absolute ethanol group,respectively.Comparing the LDH of the sal ammoniac treatment group with that of the saline group,t=8.4264,ρ=0.0000;comparing the absolute ethanol group and normal saline group,t=13.8763,p=0.0000.Comparing the SDH of the sal ammoniac treatment group with that of the normal saline group,t=8.1455,ρ=0.0000;comparing the absolute ethanol group with the normal saline group,t=7.2197,ρ=0.0000.Conclusion:The traditional Chinese antitumor medicine,sal ammoniac and its main effective components have good antitumor effect,which can be further popularized and applied in clinical practice.

Anodic Reaction of Arsenopyrite in Ammoniacal Solution

Anodic dissolution of arsenopyrite in ammoniacal solution has been investigated by electrochemical methods. The process is an irreversible reaction with formation of a ferric oxidized film and is retarded by the film. The process rate is controlled by the electrochemical reaction on the electrode surface in the lower temperature range, or alternatively by the diffusion through the film in the higher temperature range. The overall reaction has 14 electron transferred and can be expressed by FeAsS + 11H2O = Fe(OH)3 + SO42- + HAsO42- + 18H+ + 14e-, and the reaction involves two steps: (1) FeAsS + 7H2O = Fe(OH)3 + HAsO42- + S0 + 10H+ + 8e- , (2) S0 + 4H2O = SO42- + 8H+ + 6e- .

芡实对沿淮富营养化水体的净化效果研究

为了解乡土水生植物芡实对沿淮农村富营养化河流净化效果,在模拟沿淮农村地区富营养化河流的水池中种植芡实,定期监测水体中的总氮(TN)、氨氮(NH_(4)^(+)-N)、总磷(TP)、化学需氧量(COD_(Cr))、酸碱度(pH)、可溶性盐含量(EC)、溶解氧(DO)的数值变化,综合分析芡实对富营养化河流的净化效果。结果表明,芡实作为沿淮地区乡土水生植物,对富营养化的河流有着净化作用。芡实在生长过程中能吸收水体95.53%~98.45%的NH_(4)^(+)-N和99.50%~99.65%的TP,净化效果好。芡实对富营养河流中TN和COD_(Cr)的净化效果不明显,而且水体中的pH上升11.05%~11.61%,EC值增加21.12%~22%,DO增加3.82~21.77倍。芡实作为一种乡土水生植物,对沿淮地区富营养化河流具有显著的净化潜力。

Effect of Ca:Mg ratio and high ammoniacal nitrogen on characteristics of struvite precipitated from waste activated sludge digester effluent

This study revealed the relationship between the presence of calcium impurities and ammoniacal nitrogen concentration upon crystallization of struvite.The research hypothesis was that the presence of both calcium and high concentrations of ammoniacal nitrogen(328–1000 mg/L)in waste activated sludge may influence the struvite quality and acid stability.Hence,we studied the impact of Ca:Mg ratio upon morphology,particle size,purity and dissolution of struvite,in the presence of varying levels of excess ammoniacal nitrogen.X-ray diffraction revealed that up to 31.4%amorphous material was made which was assigned to hydroxyapatite.Increasing the ammoniacal nitrogen concentration and elevation of the Mg:Ca ratio maximized the presence of struvite.Struvite particle size was also increased by ammoniacal nitrogen as was twinning of the crystals.Tests with dilute solutions of organic acid revealed the sensitivity of struvite dissolution to the physical characteristics of the struvite.Smaller particles(21.2μm)dissolved at higher rates than larger particles(35.86μm).However,struvite dissolved rapidly as the p H was further reduced irrespective of the physical characteristics.Therefore,addition of struvite to low p H soils was not viewed as beneficial in terms of controlled nutrient release.Overall,this study revealed that waste activated sludge effluent with high ammoniacal nitrogen was prospective for synthesis of high quality struvite material.

焦化厂蒸氨废水中氨氮快速检测方法的研究

蒸氨废水中存在较高浓度的S^(2-),严重影响离子选择性电极法测定结果的准确性,因此,焦化厂蒸氨废水中氨氮的检测一般采用纳氏试剂比色法,但该方法操作过程烦琐、测定时间长,分析结果滞后。鉴于此,研制了全固态铵离子选择性电极,通过向废水中加入适量的醋酸锌消除S^(2-)的干扰,进而建立一种适用于蒸氨废水中氨氮快速检测的电化学分析方法。调节水样的pH至4~7,加入适量的醋酸锌,测量铵离子选择性电极与Ag/AgCl参比电极间的电位差,通过标准曲线即可快速获得水样中氨氮的浓度。该方法对氨氮的检测线性范围为0.14~1400 mg/L,检出限为0.011 mg/L,相对标准偏差RSD为1.14%~3.02%,加标回收率为99.85%~104.18%。该方法操作简便,测定时间短,可快速分析焦化厂蒸氨废水中的氨氮,并具有开发氨氮在线监测装置的良好应用前景。

低温氨氮废水处理技术及研究现状

由于低温严重抑制微生物的数量和活性,冬季的氨氮废水处理效率下降严重,达标存在很大的困难。针对上述问题,归纳了在低温条件下(≤15℃)氨氮废水去除的可选技术方法和改进工艺,包括生物脱氮改进技术、物化脱氮技术和高级氧化脱氮技术;指出了氨氮的高效经济处理以及资源化回收利用是今后低温环境下氨氮废水处理的主要发展方向。

电化学法对低浓度氨氮去除的研究

研究了电化学法去除废水中低浓度氨氮的效果和氨氮的氧化机制。考察了氯离子浓度、电流密度和pH等操作参数对氨氮氧化效果的影响。结果表明,电化学法对低浓度氨氮的去除主要通过电解过程中阳极产生的次氯酸根和羟基自由基的间接氧化作用。在氯离子质量浓度为400 mg/L、电流密度为20 mA/cm^(2)和不调节原水pH的条件下,电解150 min后氨氮质量浓度由100 mg/L降至1.7 mg/L,去除率达98.1%,无副产物亚硝酸盐氮(NO^(-)_(2)-N)产生,最终副产物硝酸盐氮(NO^(-)_(3)-N)质量浓度为1.9 mg/L,氮气选择性约为97%。

The Effects of Oxidative Pretreatment of Zinc-containing Dust on Contents of Iron and Manganese in Ammoniacal Leaching Solution and Product ion of Zinc Oxide

The zinc-containing dust was oxidatively pretreated with calcium hypochlorite,subsequently leached with ammonia/ammonium bicarbonate solution to obtain the ammoniacal leaching solution,and zinc oxide was produced by ammonia distillation of the ammoniacal leaching solution and subsequent calcination. The elements of iron and manganese could not be detected in ammoniacal leaching solution,and the extraction rate of zinc was 98.2% in ammoniacal leaching process. The zinc oxide content in the product is 99.5%(ω),and the contents of iron and manganese in the product were 0.002 8‰ and 0.000 84‰(ω), respectively. The analyses of the valence states of iron and manganese in the zinc-containing dust with and without pretreatment were performed by chemical analysis and XPS,and the possible oxidation mechanism of the oxidative pretreatment of the dust was discussed. It is concluded that Fe 2+-oxide and Mn 2+-oxide in the dust were oxidized to Fe 3+-oxide and/or its hydrate and Mn 4+-oxide and/or its hydrate by calcium hypochlorite during the oxidative pretreatment process,respectively.

不同规格的丝兰提取物对猫粪便气味及氨态氮的含量影响

该试验研究在猫饲粮中添加不同规格丝兰提取物对猫粪便气味及氨态氮含量的影响,以评估在猫饲粮中添加不同规格丝兰提取物对猫粪便的除臭效果。试验选择10只健康状况良好的猫作为1个试验组,每个重复1只。空白对照组饲喂基础饲粮,处理组Ⅰ~Ⅲ组分别在基础饲粮中添加1%不同规格丝兰提取物,试验期44d。结果表明,猫饲粮中添加丝兰提取物可减少粪便中氨气排放,降低粪便中氨态氮含量,缓解猫粪便臭味。在试验设计条件下,综合各项指标,样品2效果最好。

微气泡-电催化协同氧化降解高浓度垃圾渗滤液的研究

利用微气泡-电催化协同氧化技术对高浓度垃圾渗滤液进行降解研究,考察了电流密度、pH、微气泡通气量等工艺条件对处理高浓度垃圾渗滤液的影响,对比研究了单一使用微汽泡、双氧水、电催化及其双组合协同工艺方案去除COD和氨氮的效果,并采用Design Expert 8软件进行响应面优化协同氧化工艺。结果表明,响应面预测的最优工艺条件为:电流密度为33.3 mA/cm^(2)、通气量为8.5 L/min、渗滤液初始pH 8.5,在该条件下COD和氨氮的去除率分别为75.3%和97.1%,与预测值(COD为75.0%,氨氮去除率为95.4%)基本相符。

垃圾渗滤液处理专利技术分析

垃圾渗滤液是一种成分复杂、有机物和氨氮浓度高的环境污染物,其处理工艺的研究工作对保护环境至关重要。从专利的角度出发,对我国垃圾渗滤液处理技术专利的申请态势、专利类型、法律状态、地域分布、技术分布、主要申请人等进行分析,介绍该领域的重要专利技术,旨在为我国垃圾渗滤液处理产业的发展及未来市场需求提供有价值的信息,助力中国垃圾渗滤液处理技术的研发和推广应用。

基于膜吸收法处理垃圾渗滤液废水的研究

为了处理垃圾渗滤液废水中高浓度氨氮,通过"泡沫分离、混凝沉淀、除钙、微/超滤"和膜吸收法脱氨组合工艺对垃圾渗滤液进行预处理,以保证后续生化处理系统的稳定运行。结果表明,膜吸收前处理可有效削减垃圾渗滤液中表面活性物质、大分子有机物、悬浮颗粒物和重金属,使Zn、Cu和Pb等离子含量满足生活垃圾填埋污染控制标准(GB 16889—2008)排放要求。在渗滤液pH=11.5、流速为3.6 cm/s、吸收液浓度为2 mol/L、流速为1.1 cm/s条件下,采用4级串联的中空纤维膜组件对垃圾渗滤液进行连续处理,氨氮去除率可达到97%以上,出水氨氮质量浓度始终低于50 mg/L,过膜通量基本稳定在3.0~3.2 mg/(m^(2)·s)。

Leaching kinetics of low-grade copper ore containing calcium-magnesium carbonate in ammonia-ammonium sulfate solution with persulfate

The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentrations of ammonia, ammonium sulfate and sodium persulfate were determined. The results show that the leaching rate is nearly independent of agitation above 300 r/min and increases with the increase of temperature, concentrations of ammonia, ammonium sulfate and sodium persulfate. The EDS analysis and phase quantitative analysis of the residues indicate that bornite can be dissolved by persulfate oxidization. The leaching kinetics with activation energy of 22.91 kJ/mol was analyzed by using a new shrinking core model （SCM） in which both the interfacial transfer and diffusion across the product layer affect the leaching rate. A semi-empirical rate equation was obtained to describe the leaching process and the empirical reaction orders with respect to the concentrations of ammonia, ammonium sulfate and sodium persulfate are 0.5, 1.2 and 0.5, respectively.

关于氨浸钼渣用于特殊钢冶炼的实践与思考

在钼酸铵生产过程中产生的氨浸钼渣,通常在回收后用于生产钼铁合金或作为固体废物外排。文章尝试使用氨浸钼渣直接作为合金添加剂用于特殊钢冶炼,经过工业标定氨浸钼渣中钼元素收得率可达到95%以上,使用氨浸钼渣生产的钢材能够满足质量标准要求,降低了炼钢生产成本。