Pressure Solution of Sulphides in Some Massive Sulphide Zinc-lead Deposits of Western Canada:Its Significance in Mobilization of Ore-forming Materials

Pressure solution is a common phenomenon in massive sulphide zinc-lead deposits of western Canada and may have been an important factor leading to the mobilizahon of ore-forming materials during diagenesis, deformation and metamorphism of sedimentary ores. The control of ductile shear zones over gold mineralization could be explained in view of pressure solution of gold-bearing miner-als under shearing stress and the resultant mobilization of this metal.

Crystallization behaviors of bayerite from sodium chromate alkali solutions

In order to clean production of chromium compounds, it is a critical process to remove aluminates and utilize aluminum compounds from artificial chromate alkali solutions. The effects of Na2 Cr O4 on the neutralization curve, Al（OH）3 precipitation efficiency and induction period of bayerite were investigated. The results indicate that the neutralization curve of the artificial chromate alkali solutions shows three distinct regions and its induction period is longer than that of pure sodium aluminate solutions at the same aluminum concentration. And the decreased temperature and volume fraction of CO2 enhance the particle size of bayerite β-Al（OH）3. Bayerite composed of agglomerates of rods and cone frustums was obtained from alkali metal chromate solutions with 28.5% CO2（volume fraction） at temperatures ranging from 50 °C to 70 °C. Coarse bayerite with particle size（d50） from 24.2 μm to 29.3 μm extremely has few impurities, which is suitable for comprehensive utilization.

Seed-solution-induced Synthesis of FER Zeolite and Its Catalytic Application in the Skeletal Isomerization of n-Butene

A series of Ferrierite(FER)zeolites were prepared via hydrothermal synthesis in the absence of organic templates with the aid of sodium-type FER zeolite(NaFER)or NaFER suspensions(NaFERsus)acquired by NaOH solution treatment as seeds.The differences in the structures and acid sites of the obtained FER zeolite catalysts arising from the choice of seed were investigated,and the catalytic performances of the obtained FER zeolites were evaluated in the skeletal isomerization of n-butene.The results indicate that the samples synthesized using NaFERsus feature more Br?nsted acid sites(BAS)in the 10-membered-ring(10-MR)at the expense of strong acid and Lewis acid sites(LAS),compared with samples derived from NaFER.Therefore,the FER samples synthesized using NaFERsus outperformed the NaFER counterparts as the BAS in 10-MR and LAS were the main active sites,while BAS in 8-MR and LAS were responsible for side reactions,such as polymerization,cracking,and carbon deposition in n-butene isomerization.The optimized FER catalyst was continuously used for 720 h at 350℃ at 0.1 MPa under an n-butene space velocity of 2.0 h^(-1),during which the n-butene conversion remained at>40%,and the isobutylene yield was>37.5%.

Experimental studies of air-blast atomization on the CO_(2)capture with aqueous alkali solutions

In this work,an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA(mono-ethanol-amine)and Na OH solutions.The effects of gas flow rate,the liquid to gas ratio(L/G),the CO2 concentration on the CO2 removal efficiency(η)and the volumetric overall mass transfer coefficient(KGav)were investigated.The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance.For the aqueous MEA and Na OH solutions,the experimental results show that theηdecreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G.The effects on KGavare more complicated than those forη.When the CO2 concentration is low(3 vol%),KGavincreases with increasing gas flow rate while decreases with increasing L/G.However,when the CO2 concentration is high(9.5 vol%),as the gas flow rate and L/G increases,KGavincreases first and then decreases.The aqueous MEA solution achieves higherηand KGavthan the aqueous Na OH solution.The air-blast atomizing column shows a good performance on CO2 capture.

Calculation of Interaction Parameters from Immiscible Phase Diagram of Alkali Metal or Alkali Earth Metal-Halide System by Means of Subregular Solution Model

In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpressed as follows:Gm^E=xAxB[(λ11+λ12T)+(λ21+λ22T)xB]The calculation of the model parameters, λ11, λ12, λ21and λ22, was carried out numerically from the phase diagrams for 11 alkali metal-alkali halide or alkali earth metal-halide systems. In addition, artificial neural network trained by known data has been used to predict the values of these model parameters. The predicted results are in good agreement with the .calculated ones. The applicability of the subregular solution model to the alkali metal-alkali halide or alkali earth metal-halide systems were tested by comparing the available experimental composition along the boundary of miscibility gap with the calculated ones which were obtained by using genetic algorithm. The good agreement between the calculated and experimental results across the entire liquidus is valid evidence in support of the model.

Investigation on Nonwovens Leukocyte Filtering Materials Treated with Amine and Alkali Solution

Filtering materials are chosen according to the mechanism of blood filtration and mathematics model, then the material is treated with amine and alkali solution. There is cooperation and synergism between alkali and amine, and the actions are realized in three stages. After modification the material treated has accessibility groups NH 2 , and slits appeared in the surface of fiber, so the wettability of materials is improved distinctly; the diameter and aperture of fiber have no changes basically.

Low-concentration sodium hydroxide solution injection in normal liver parenchyma of rabbits

BACKGROUND: Percutaneous ethanol injection has been widely used as a non-surgical therapy for liver cancer, but it has some shortcomings such as local diffusion and une- qual permeation. This study was designed to observe the volume, controllability and completeness of necrosis after injection of low concentration sodium hydroxide in the normal liver parenchyma so as to assess its possibility in treatment of liver cancer instead of ethanol. METHODS: Twenty-seven New Zealand rabbits were di- vided randomly into 9 groups (Aa, Ab, Ac, Ba, Bb, Bc, Ca, Cb, and Cc) by a 3 × 3 (three-by-three) factorial de- sign, each consisting of 3 rabbits. Group A was given sodi- um hydroxide solution at a concentration of 5%, while B at 2.5% and C at 1% in liver parenchyma. Each group re- ceived three doses of the solution: a (0.2 ml), b (0.5 ml) and c (1.0 ml). Then another 3 rabbits as side-effect group were dropped with sodium hydroxide solution in their liver lobe space. Liver and renal function changes in all the rab- bits were compared after injection with pre-injection. RESULTS: All the lesions were localized. At the concentra- tion of 2.5% and 5%, the lesion volume increased with the dose increased from 0.2 ml to 1.0 ml (P < 0. 05). No sig- nificant differences were found in the lesion volume of the groups receiving the same dose but different concentration. Changes in liver and renal function were not significant 7 days after injection, compared with those before injection. CONCLUSIONS: 2.5% and 5% sodium hydroxide solution could control local complete necrosis in normal liver. With regard to safety, 2.5% alkali solution is considered promis- ing as a new agent for intratumoral injection therapy in- stead of ethanol.

Bioleaching of low-grade copper sulphides

The bioleaching behavior of low-grade copper sulphides under the condition of preferential solution flow was investigated through experiments. The experiment of bioleaching was conducted within the multifunction autocontrol bioleaching apparatus. The results show that the concentrations of Cu2+ and total Fe increase slowly at the beginning. The recovery rate decreases with the increase of depth of dump. The preferential solution happens within the fine region when the application rate is low, and the recovery rate of the fine region is higher than that of the coarse region. The content of fine ore particles within both fine and coarse regions increases during the leaching period, and the preferential solution flow shifts from fine region to coarse region. The surface of the ores at the top of dump is attacked seriously, and the ores in the middle is attacked slightly. There are plenty of crackles on the surface of bottom ores because of the precipitation layer on the surface.

废旧磷酸铁锂电池集流体分离与正极材料再生

通过优化NaOH碱溶条件高效去除集流体黏结剂,保留完整铝箔;利用固相法再生LiFePO 4。当NaOH为0.8 mol/L、固液比20 mL/g、40℃反应10 min,正极材料的分离率达到99.78%,超声1 min后铝箔回收率为76%,解决了碱溶条件下铝箔回收的繁琐问题。球磨转速500 r、球磨5 h,补充10%高纯LiFePO 4的方式固相再生,再生LiFePO 4的最高放电比容量为新材料的94.75%,60次循环测试后为初始放电比容量的88.62%。

不同干燥方式对南极磷虾分离蛋白结构及功能特性的影响

采用碱溶酸沉的方法提取南极磷虾分离蛋白(krill protein isolate,KPI),通过喷雾干燥和冷冻干燥的方式制备南极磷虾分离蛋白粉,并对这两种分离蛋白粉的结构及功能特性进行比较分析。结果表明:与冷冻干燥南极磷虾分离蛋白(freeze-dried krill protein isolate,FKPI)相比,喷雾干燥南极磷虾分离蛋白(spray-dried krill protein isolate,SKPI)明度大,色泽较好;扫描电子显微镜结果显示,SKPI呈现出向内凹陷的不规则球状结构,而FKPI为薄层片状结构,SKPI的堆积密度高于FKPI;圆二色谱进一步表明,与KPI相比,SKPI和FKPI均呈现α-螺旋含量下降、β-转角含量增加的趋势,其中,SKPI的α-螺旋含量下降27.9%,β-转角含量增加12.2%,表明喷雾干燥后蛋白质的二级结构均从有规则的结构向无规则的结构转化;SKPI持水力、持油力、乳化稳定性和起泡性等均高于FKPI,而SKPI的溶解性、乳化性却比FKPI的差。可见,不同的干燥方式会改变南极磷虾分离蛋白的结构特性,并进一步影响其功能特性。

碱激发矿粉胶凝材料固化高含盐量浓缩液污泥试验研究

采用浸没式燃烧工艺处理生活垃圾填埋场渗滤液产生的浓缩液污泥副产物具有高易溶盐含量的特征。分别采用硫铝酸盐水泥和碱激发矿粉胶凝材料固化浓缩液污泥,对固化试样进行一系列无侧限抗压强度(UCS)试验、水稳定性试验和微观观测试验,分析硫铝酸盐水泥和碱激发矿粉胶凝材料对浓缩液污泥的固化效果和固化机理。研究结果表明:40%水泥掺量的固化试样的28 d无侧限抗压强度为1.95 MPa,浸水28 d后降低至零。30%矿粉掺量的固化试样的28 d无侧限抗压强度为14.8 MPa,浸水28 d后,仍达3.6 MPa,远大于垃圾填埋场的填埋强度要求。碱激发矿粉反应生成的三维网状胶凝材料和钙矾石晶体可对浓缩液污泥颗粒实现有效的包裹和胶结,是碱激发矿粉胶凝材料固化浓缩液污泥的微观固化机制。

适宜陇中盐碱地改良的藜科植物材料筛选与效果评价

在甘肃省兰州市七里河区种植4种13份乡土藜科植物材料并观测其田间农艺性状和土壤化学性质,筛选适宜陇中地区的减盐植物和土壤改良植物。结果表明,盐生草、猪毛菜、中亚滨藜、角果碱蓬4种乡土藜科植物中,材料203(猪毛菜)的生物量最大,材料109(角果碱蓬)的株高最高。与未种植藜科植物的土壤相比,多数藜科植物材料的种植能提高土壤浅层(0~10 cm)的有机质、碱解氮、速效磷、速效钾、全氮和全磷含量,提高了土壤(0~30 cm)的全钾含量,同时,降低了0~30 cm土层的pH值和0~20 cm土壤溶液的电导率。13份材料中,材料95(盐生草)对0~20 cm土层有明显的降盐作用。综合评价结果表明,材料303(角果碱蓬)得分最高,是陇中地区适宜的盐碱地改良植物。

佯黄竹置换蒸煮工艺研究

结合单因素实验法和Box-Behnken响应面法研究了用碱量、硫化度、液比、不同蒸煮阶段用碱量的配比、最高蒸煮温度和保温时间对佯黄竹置换蒸煮(DDS)效果的影响。单因素实验结果表明,佯黄竹DDS蒸煮的浆料卡伯值受用碱量、硫化度、最高蒸煮温度和保温时间的影响较大。通过响应面实验对用碱量、硫化度和保温时间进行进一步优化,得到非线性回归方程。方差分析和显著性测试结果表明,所拟合模型拟合程度较高。对方程求解得出最优佯黄竹DDS蒸煮工艺条件为:用碱量23.0%(NaOH计)、硫化度18%(Na2 S计)、液比1∶4.5、最高蒸煮温度160℃、保温时间70 min、用碱量质量比(预浸渍段︰温充段︰热充段)为20∶20∶60。在该蒸煮条件下的细浆得率为49.0%,竹浆卡伯值可降低至16.2。

苛碱体系低模数硅酸钠溶液的结构

通过红外光谱测试技术,研究二氧化硅质量浓度、模数以及放置时间对苛碱体系低模数m(m≤1)硅酸钠溶液结构的影响,比较纯硅酸钠溶液和预脱硅溶液在结构上的差异。研究结果表明:苛碱体系预脱硅溶液结构与纯硅酸钠溶液结构相似,模数0.75≤m≤1.00,ρ(SiO2)≤20 g/L的硅酸钠溶液主要含有硅氧环状和三元环状这2种复杂阴离子;模数m≤0.50、30≤ρ(SiO2)≤50 g/L的硅酸钠溶液以单体和线型这2种简单形态出现;钠硅渣形成过程主要消耗单体硅酸根离子,ρ(SiO2)=50 g/L左右的预脱硅溶液结构稳定,溶液中的铝酸根离子不会影响硅酸根离子结构。

碱溶液提取-电感耦合等离子体原子发射光谱法测定土壤中六价铬的含量

针对HJ 1082-2019存在的检测范围窄、高盐分带来的基线漂移以及谱线干扰等情况,提出了题示方法。取样品5.0 g,加入50 mL含0.5 mol·L^(-1)氢氧化钠和0.28 mol·L^(-1)碳酸钠的碱提取液(pH>11.5)、0.4 g氯化镁和0.5 mL磷酸盐缓冲液(pH 7.0),放入40 mm磁子,于95℃以速率600 r·min^(-1)搅拌60 min,冷却,以转速4000 r·min^(-1)离心5 min。分取滤液25 mL,调节酸度至pH 7.0~7.5,然后用水定容至50 mL。分取1 mL,用水稀释10倍后,采用电感耦合等离子原子发射光谱法测定其中六价铬的含量。结果表明:六价铬标准曲线的线性范围在2 mg·L^(-1)以内,检出限(3.143s)为0.096 mg·kg^(-1);5种土壤中六价铬成分分析标准物质的测定值均在认定值的不确定度范围内,且测定值的相对标准偏差(n=6)为1.1%~3.7%;按照标准加入法对实际样品进行加标回收试验,回收率为90.0%~112%。

氯乙烯碱洗塔自动配碱改造

针对氯乙烯碱洗塔内碱液浓度波动大、加入量不稳定,人工配碱准确度差、劳动强度高等问题,进行了自动配碱工艺改造,介绍了改造方案、自动配碱程序的设置及改造效果。改造后提升了自动化水平,提高了系统运行的稳定性,降低了安全风险。

辣椒籽分离蛋白超滤提取工艺优化及特性表征

辣椒籽作为辣椒加工过程中的主要副产物,富含蛋白等营养物质,却未能得到有效利用。基于此,该研究以益都红辣椒籽为原料,采用超滤辅助碱溶酸沉法提取辣椒籽分离蛋白,并与传统碱溶酸沉法提取的辣椒籽分离蛋白的综合提取率、物料投入以及理化和功能特性进行对比。传统碱溶酸沉工艺提取辣椒籽分离蛋白的最佳工艺参数为料液比1∶40、提取温度40℃、提取时间180 min、浸提次数1次、碱溶pH 10。为提高蛋白提取量,减少调节pH的酸碱用量,改善分离蛋白的理化特性,采用5 kDa和10 kDa的双级膜超滤技术辅助碱溶酸沉法获得3个超滤组分,包括>10 kDa蛋白、5~10 kDa蛋白和<5 kDa蛋白,蛋白提取量较传统碱溶酸沉法提高5.28%,盐酸用量较传统碱溶酸沉法减少19.48%。相比于传统碱溶酸沉法提取的蛋白,>10 kDa蛋白的溶解度、持水力、乳化稳定性分别显著提高了9.88%、78.66%、22.69%,说明超滤辅助碱溶酸沉法能够获得理化特性更佳的辣椒籽分离蛋白,是一种具有应用前景的辣椒籽分离蛋白提取手段。

山体隧道洞渣碱活性评定及碱骨料反应抑制措施研究

对某高速隧道洞渣进行了碱活性判定,从密实性和疏水性方面提出了碱骨料反应抑制措施,并通过膨胀率、强度综合评价抑制效果,从吸水率、孔溶液中碱含量探究了抑制机理。结果表明:洞渣骨料属于高活性碱-硅酸骨料,存在碱骨料反应风险;控制粉煤灰掺量不低于30%可有效抑制洞渣碱骨料反应;采用10%~12%的RMA纳米防腐剂或2.5%~7.5%的TIA抗侵蚀抑制剂优化单掺30%粉煤灰可以兼具强度保障和碱骨料反应抑制;单掺粉煤灰、复掺粉煤灰和RMA纳米防腐剂主要通过降低孔溶液中游离态的碱离子,实现碱骨料反应的抑制;复掺粉煤灰和TIA抗侵蚀抑制剂主要通过碱离子和吸水率的双重降低,实现碱骨料反应的抑制。

离子膜电解槽碱液流量计波动原因

分析离子膜电解槽配备的碱液流量计显示值低于实际值的原因有:电磁干扰,安全仪表系统控制器故障,流量计未接地,流量计安装偏差或其他工艺因素。针对以上原因提出相应的技改措施。实施后,可以快速有效排除故障。

超声辅助—碱溶液提取火焰原子吸收分光光度法测定土壤和沉积物中的六价铬

本文建立了超声辅助-碱溶液提取火焰原子吸收分光光度法测定土壤和沉积物中六价铬的方法,与国标HJ 1082-2019方法相比,采用pH=11的NH_(4)OH-NH4Cl溶液作为提取剂,98±2℃热水中超声辅助提取60min,离心机分离,再加入无水硫酸钠作为信号增强剂进行测定,避免了HJ1082-2019提取步骤繁琐、生成大量沉淀、分离效率低的缺点。该方法的检出限为0.49mg/kg,测定下限为1.96mg/kg,相对标准偏差(RSD,n=6)为2.9%~3.4%,加标回收率为94.2%~100.8%,具有操作简单、准确度高、批量处理样品效率高等优点。