铝酸钠溶液中硅酸二钙的分解及抑制

分析了在氧化铝生产的熟料溶出过程中影响硅酸二钙分解的因素,通过试验研究了碳酸钠和添加剂对硅酸二钙分解的抑制作用,并对添加剂的抑制机理进行了探讨。     

氧化锌低酸上清经还原再用锌浮渣或氧化锌焙砂沉铟试验研究

针对某厂富集工段铟富集渣渣率大、铟品位低、杂质含量高等问题,以氧化锌低酸上清为铟富集原料,开展了低酸上清直接用锌浮渣沉铟、低酸上清经还原再用锌浮渣和氧化锌焙砂沉铟等试验。结果表明,低酸上清直接用锌浮渣或经还原再用氧化锌焙砂沉铟,所得铟富集渣渣率大、铟品位低且难以过滤,而低酸上清经还原再采用锌浮渣沉铟能较好地解决上述问题,铟富集渣含铟品位在2.5%以上,且杂质含量也低。     

氧化锌低酸上清经还原再用锌浮渣或氧化锌焙砂沉铟试验研究

针对公司富集工段铟富集渣渣率大、铟品位低、杂质含量高等问题,以氧化锌低酸上清为富集铟原料,开展了氧化锌低酸上清直接用锌浮渣沉铟,氧化锌低酸上清经还原再用锌浮渣或氧化锌焙砂沉铟等研究试验,同时考察了F、CI、As等元素在沉铟前后溶液中的变化。结果表明,氧化锌低酸上清直接用锌浮渣沉铟及经还原再用氧化锌焙烧沉铟,得到的铟富集渣渣率大、铟品位低及难以过滤等问题,而氧化锌低酸上清经还原采用锌浮渣沉铟较好地解决了上述问题,铟富集渣含铟品位在2.5%以上,且杂质含量也低。     

碱性氧压体系下高砷锑烟灰分离砷的工艺研究

采用氧气为氧化剂,氢氧化钠为浸出剂,在加压条件下从高砷锑烟灰中分离砷。研究了碱性氧压体系下氢氧化钠加入量、浸出温度、液固比、氧分压、反应时间、搅拌速率对砷锑浸出率的影响,并得到了较优工艺条件。在NaOH加入量为理论量1.3倍、浸出温度130 ℃、液固比4、氧分压为0.7 MPa,反应时间2 h,搅拌速率600 r/min的优化条件下,As、Sb浸出率分别为93.54%,0.73%。     

赤泥磷酸浸出选择性脱硅

赤泥是铝土矿生产氧化铝过程中产生的固体残渣，也是一种低品位含铝资源，但因其SiO2含量高、铝硅比低，难以直接通过碱浸回收Al2O3。以赤泥钠化还原焙烧—磁选后所得非磁性物为原料，磷酸为浸出剂，实现了硅的选择性浸出及铝、硅之间的有效分离，为后续氧化铝的提取创造了有利条件。在磷酸浓度1 mol/L、液固比15 mL/g、浸出温度50 ℃、浸出时间60 min的条件下，SiO2的浸出率达82%，浸出渣铝硅比为4.4，较非磁性物提高了2倍左右，实现了铝、硅之间的较好分离。磷酸浸出渣再碱浸，采取35% NaOH溶液，浸出温度260 ℃，Al2O3的浸出率从未脱硅前的69%增大至93%。磷酸选择性浸出非磁性物中硅的原因是铝硅酸盐矿物中含硅组分溶解在酸溶液中，而含铝组分与磷酸反应转变成了"AlPO4 " 不溶性沉淀。     

铂钯精矿氧压硫酸浸出液中除铁试验

分别采用N235萃取法、铁矾法、赤铁矿法从铂钯精矿的氧压硫酸浸出液中除铁,并对三种方法的利弊、成本、试验条件等进行比较。结果表明,铁矾法和赤铁矿法的铜离子损失量和渣量均较大,萃取法具有有价金属损失小,无渣等优点,值得进一步开发。     

铝酸钠溶液碳分—超声酸洗制备高纯Al_2O_3

研究了分解温度、CO_2气体浓度、Al_2O_3浓度和分解时间对铝酸钠溶液碳分Al_2O_3分解率的影响,以及碳分后得到的氢氧化铝粉体在酸洗过程中超声波酸洗对产品氧化铝纯度的影响。结果表明,在溶液浓度105g/L、溶液苛性分子比αk=1.50时,控制碳酸化分解温度60℃左右,CO_2浓度30.0%,分解时间4h,分解率达到93%,碳分后得到的氢氧化铝粉体在普通酸洗条件下得到的Al_2O_3含量为99.87%,超声波酸洗后得到的Al_2O_3含量可以达到99.99%。     

Removal of Nickel(II) from Dilute Aqueous Solution by Sludge-Ash

This work examines the adsorption of Ni(II) onto sludge–ash, a waste produced from a fluidized bed incinerator combusted primarily with biosolids. Results of kinetic experiments showed that the adsorption was rapid. The kinetic adsorption data can be well described by an empirical modified Freundlich equation. The rate of adsorption decreased with either increasing surface loading and ionic strength or decreasing solution pH. The results of equilibrium studies showed that the solution pH was the key factor affecting the adsorption. The modified Langmuir model fit revealed that the hydrogen ion acts as a competitive inhibitor for the adsorption of Ni onto ash. The maximum adsorption capacity for Ni is 5.41 μmol/g. Experimental results indicate that the adsorption is favorable at higher temperature. Thermodynamic adsorption parameters for ΔG°, ΔH°, and ΔS° are ?7.41 kcal/mol, 7.25 kcal/mol, and 48.9 cal/mol?K, respectively.     

铁矾渣酸浸液磷酸除铁副产磷酸铁性能研究

针对本研究团队提出的"铁矾渣活化焙烧-稀酸酸浸-酸浸液磷酸除铁-除铁后液提In和Zn"新工艺,本文重点研究磷酸除铁滤渣物性及热分析动力学。通过XRD、IR、TG-DSC等对磷酸除铁滤渣的组成和物相进行分析表征。结果表明,磷酸除铁滤渣为FePO_4·2H_2O,滤渣平均直径12.6μm。采用FWO、KAS两种等转化率法求得滤渣磷酸铁水合物脱水反应的活化能为47.28～52.88kJ/mol。     

锌铅合金锌粉净化除钴的研究

进行硫酸锌溶液净化除钴时,多采用锑盐－锌粉法。在该法技术条件基础上研究了锑盐－锌铅合金锌粉除钴的效果及其对钴返溶的抑制,认为锑盐－锌铅合金锌粉除钴在技术上可行,经济上合理。     

石煤钒矿碱法提钒浸出液净化过程中回收白炭黑的工艺研究

对石煤钒矿碱法提钒浸出液的净化过程进行研究,通过控制中和剂的浓度、滴加速度、溶液的pH值、反应温度、时间、搅拌速度,净化渣含SiO2达到96.96％,符合白炭黑成分的要求,净化过程V2O5收率稳定在99％以上.     

纳米零价镍去除溶液中U(VI)的研究

采用液相还原法制备纳米零价镍,并用来去除溶液中的U(VI)。通过SEM、EDS技术表征反应前后材料的形貌,从微观角度分析纳米零价镍去除溶液中U(VI)的机理,并进行了热力学分析。结果表明,纳米零价镍对溶液中U(VI)有良好的去除效果,在室温下,pH=4.0、接触时间60min、固液比0.3g/L和初始浓度50mg/L时,U(VI)的去除率和去除量分别达到了98.44%和182.372mg/g。新制备的纳米零价镍呈明显的球状,颗粒较为分散且粒径较均匀,反应后,材料表面形貌发生变化,呈不规则碎片堆积、粒径变大,且材料中出现了铀元素。热力学研究结果表明,该反应是自发吸热反应,同时也是不可逆的熵增反应。     

纳米铁镍双金属去除溶液中U(VI)的研究

采用同步液相法制备纳米Fe/Ni双金属来去除溶液中的U(VI),通过BET、SEM等方法对双金属材料进行表征分析,用批试验法研究n(Fe)/n(Ni)比、pH、初始铀浓度、反应时间和温度对去除U(VI)的影响。结果表明,铁镍双金属体系去除U(VI)的最佳pH为3.5,反应平衡时间为30 min,25 ℃时的饱和吸附量为161.91 mg/g。     

PFS法处理镍钼矿酸浸液萃钼余液的研究

采用聚合硫酸铁(PFS)法处理镍钼矿酸浸液萃钼余液中的重金属离子和化学耗氧量(COD),考察双氧水用量、PFS用量、搅拌时间、pH对余液中Zn~(2+)、Pb~(2+)、Ni~(2+)及COD含量的影响。结果表明,在双氧水用量20 mL/L、PFS用量60 mg/L、搅拌时间90 min、pH 11.0的条件下,COD可降至500 mg/L以下,去除率高达89%,重金属离子均达到GB 8978-1996污水综合排放一级标准。     

Leaching of copper(I) sulphide by sulphuric acid solution with addition of sodium nitrate

Finely grained samples of copper(I) sulphide were leached by H₂SO₄ solution with added NaNO₃. The occurrence probability of chemical reactions was analysed based on literature data and products which were formed during the process and the overall leaching reaction was defined. The effect of temperature, concentration of NaNO₃ and H₂SO₄, stirring speed, phase ratio and time, on the leaching degree of copper was studied. The quantity of copper dissolved increases with growth of the values of all the parameters. Kinetic analysis shows that the leaching mechanism is very complex. By using appropriate mathematical kinetic models, it is found that the leaching rate is chemically controlled. It was concluded that the leaching reaction is first order with respect to the concentration of NaNO₃ and second order with respect to the concentration of H₂SO₄.     

Fe(OH)3吸附法从高钨钼酸钠溶液中分离钨钼的研究

研究了用Fe（OH）3吸附法从高含钨的钼酸钠溶液中分离钨的可能性及技术条件。试验表明，在pH=7．0和Fe（OH）3用量为WO4^2-量2～4倍的条件下，每次吸附能分离70％～80％的钨。对WO3／MO=0．445的物料而言，经一次吸附可使WO3/Mo降为0．17～0．18。试验中开发了一种以HCl＋NH4Cl作中和剂将Na2MoO4溶液中和的新方法，采用这种方法可显著提高回收率及分离效果。     

氯化铵焙烧法分解氟碳铈精矿制备晶型碳酸稀土的研究

采用脱氟剂将氟碳铈精矿中的氟转化为水溶性氟洗去,再用氯化铵焙烧法分解经预脱氟的氟碳铈精矿,直接用水浸取稀土。考察了反应温度、时间、氯化铵用量及脱氟剂用量对该矿稀土提取率的影响,脱氟精矿在焙烧温度４８０℃,焙烧时间１．５ｈ,氯化剂／矿重＝ ２．０ 时,稀土提取收率达８４．３％ 。其氯化选择性高,浸出液中Ｆｅ、Ａｌ、Ｓｉ等非稀土杂质分别为稀土的０．１０％ 、０．００５％ 和０．０１６％ ,经碳酸氢铵沉淀,获得了晶型碳酸稀土（折算稀土氧化物纯度９２．０７％ ）产品。     

Precipitation of nanosized titanium dioxide from aqueous titanium(IV) chloride solutions by neutralization with MgO

Aqueous titanium (IV) chloride solutions were neutralized to different terminal pH (2.5 to 6.0) with magnesium oxide as base at 95 °C and were found to yield nanosized titanium dioxide. The produced materials were compared to those obtained by simple forced hydrolysis. The techniques of XRD, TGA–DTA, FT-IR, BET, SEM and TEM were applied for the characterization of the produced materials. Honeycomb-shaped uniform nanosized crystalline TiO₂ powders with aggregate particle size of about 50 nm were successfully obtained by neutralization with magnesium oxide. Phase-pure rutile or mixed rutile and anatase crystalline TiO₂ powders were precipitated with proper selection of conditions. It was found that forced hydrolysis at 95 °C favors the formation of rutile TiO₂. Rutile TiO₂ powders with different crystallite sizes between 11 and 18 nm were obtained from aqueous TiCl₄ solutions with Ti concentration ranging from 0.5 mol/L to 2.0 mol/L. Neutralization with MgO at 95 °C, on the other hand, favored the formation of mixed anatase and rutile materials. The anatase fraction (ranging from 0 to 70%) increased with pH elevation (from 2.5 to 6.0). The neutralization method yielded much higher titanium precipitation efficiency (up to 100%) than simple forced hydrolysis. The magnesium content in the TiO₂ products was found to increase with a rise in the final pH due to partial hydrolysis of magnesium. It was less than 0.1% when the final pH was kept at or below 3.3.     

用环烷酸石油亚砜从混合氯化稀土溶液中萃取分离钇

进行了用环烷酸石油亚砜从混合氯化稀土溶液中萃取分离钇的研究。用混合室体积为 1 2 0 L混合澄清槽 ,经 1 2 0级串级分馏萃取分离 ,可获得纯度大于 99.99%的 YC1 3溶液。与环烷酸混合醇体系相比 ,环烷酸石油亚砜体系的分相性能及有机相流动性更好。分离出的 YC1 3溶液经进一步分离非稀土杂质后 ,可用于制取荧光级 Y2 O3产品 ,产品收率可达 90 .5%。     

用AAS研究胡椒基荧光酮与钍（Ⅳ）的显色反应

应用原子吸收分光光度计对胡椒基荧光酮与钍(IV)的显色反应条件进行了研究 ,体系λmax 为560nm,ε为1.12×105L·mol -1·cm -1。钍(IV)含量在0～25μg·(25mL) -1内符合比耳定律 ,方法用于地球化学标准样中钍的测定 ,结果和参考值吻合。