含砷废渣的固化处理

为了处理有色金属冶炼厂产生的含砷废渣（简称砷渣）,以水泥、粉煤灰、矿渣、黄砂等作为固化材料对砷渣进行了固化研究。确定了砷渣固化的最佳工艺条件：w（砷渣）：50％、w（水泥）=15％、w（粉煤灰）：20％、w（矿渣）=10％、w（黄砂）=5％;砷渣、粉煤灰预先混合球磨10min,加水搅拌后陈化4h,烘干后与水泥、矿渣一起球磨20min,再与水（水与混合物料的质量比为0．175）、添加剂（质量分数为0．05％的添加剂B）及黄砂一起在搅拌机中搅拌6min,然后加压成型,成型后的固化体先放入24℃水泥砼试体养护箱养护14d,然后取出在室温下自然养护14d,养护时间共28d。扫描电子显微镜分析结果显示,砷渣固化体的胶凝状态良好。测试结果表明,砷渣固化体7d抗压强度为8．13MPa,28d抗压强度为14．20 MPa;As的浸出浓度为0．07mg／L,Hg的浸出浓度为0．008mg／L。砷渣固化体的性能达到了国家建材行业标准（JC239-2001《粉煤灰砖》）和危险废物鉴别标准（GB5085．3～1996《危险废物答别标准——浸出毒性答别》）的要求。     

从电镀废渣中回收有价金属

该发明涉及一种从电镀废渣中回收有价金属的方法：（1）用稀酸将电镀废渣中的有价金属浸出，经过滤分离出酸浸渣和酸浸液；（2）在85～100℃用硫化物沉淀出酸浸液中的铜，经过滤分离出硫化铜和沉淀母液；（3）将质量分数5％～20％的碱溶液加入沉淀母液中，并控制溶液的pH为5．0～6．0，使溶液中的铬、铝沉淀，过滤分离出铬、铝渣及含铁、锌、     

铬渣钡渣代替天然砂制作混凝土的研究

用铬渣、钡渣代替部分天然砂制作强度等级为C15的普通混凝土,混凝土的强度等级与钡渣、铬渣的加入量关系较大.用PO32.5标号水泥,铬、钡渣的质量代替砂子质量的50%时,混凝土的抗压强度达到18.9MPa,比普通混凝土设计的抗压强度提高26%,混凝土的收缩量为1/300,优于国家标准,对混凝土作浸出毒性试验,Cr6+和Ba2+都远小于国家规定的标准值.     

碱性氧化焙烧回收含铬污泥中的铬

采用碱性氧化焙烧工艺回收含铬污泥中的铬,以浸出渣作为焙烧填料,最佳工艺条件为：含铬污泥加入量10g,浸出渣加入量8g,焙烧温度700℃,焙烧时间40min,n（Cr2O3）：n（NaNO3）：n（Na2CO3）：n（NaOH）=1：2：3．5：10。在此条件下,碱性氧化焙烧工艺铬浸出率高达98％以上。     

一种适用于盐渍土的土壤固化剂

一种适用于盐渍土的土壤固化剂，可用于含盐量高的盐渍土的固化。各原料的质量组成：普通硅酸盐水泥1．0％，粉煤灰1．5％-2％，水淬高炉矿渣2％-3％，活性矿物掺和料（煅烧媒矸石粉、亚高岭土、磷渣或镁渣中的一种或几种）1．0％-1．5％，石灰（生石灰粉或消石灰）0．5％-1．5％，碱金属或碱土金属的氢氧化物0—0．3％，化学分散剂（萘璜酸盐缩合物或密胺类物质）0—0．1％。     

一种保温混凝土空心砌块及其制备方法

该专利公开了一种保温混凝土空心砌块的制备方法。由水泥、石渣粉、聚苯乙烯颗粒、增黏剂、水为原料制成，其各成分配制质量比为水泥：石渣粉：聚苯乙烯颗粒：增黏剂：水=1：（6～9）：（0．005～0．05）：（0．01～0．02）：（0．35～0．5）；经搅拌、成型、静置1d后，再经养护后制得空心砌块。该砌块中含有适量的聚苯乙烯颗粒，砌块混凝土的导热系数降至0．5W／（m^2·K）左右，     

强酸性硫化砷废渣的稳定固化

采用污泥、石灰、氧化镁和水泥等药剂稳定固化强酸性硫化砷废渣(简称砷渣)。以浸出液中砷的质量浓度为考核指标,采用正交实验考察了稳定化药剂加入量对废渣浸出毒性的影响。实验结果表明:污泥加入量是影响废渣浸出毒性的最主要因素;在m(污泥):m(砷渣)=2.0、m(石灰):m(砷渣)=1.0、m(氧化镁):m(砷渣)=0.10、m(水泥):m(砷渣)=0.3的最佳实验条件下,砷的浸出质量浓度由1780.00 mg/L降至1.37 mg/L,低于GB 18598—2001《危险废物填埋污染控制标准》中砷浸出质量浓度为2.5 mg/L的填埋限值;处理后废渣中其他金属的浸出质量浓度也低于标准限值。     

废铬渣无害化处理工艺方法

该发明公开了一种废铬渣无害化处理工艺。将废铬渣40％～45％、粉煤灰10％～15％、锌窑渣10％～15％、赤泥28％～30％（均为质量分数）混合均匀，破碎至50～80目后送入烧结炉内，于1000～1100℃高温下进行还原烧结物化处理，烧结后的混合料冷却2～3h后用水浸泡20～26h，用滤布滤出渣料，滤液用FeSO4作还原剂，其加入量为废铬渣中Cr^6＋含量的14～16倍，在滤液pH为8～8．5的条件下进行还原反应；将烧结过程产生的废气送至洗涤塔洗涤，产生的水蒸气排空。     

铬渣无害化处理技术研究进展

综述了铬渣无害化处理技术的研究进展,分析了各种技术在实际应用过程中的效果,指出各种处理技术的优缺点,详细介绍了固化法中水泥固化和药剂稳定化两种处理技术,提出开发重金属螯合剂是今后铬渣稳定化处理的研究方向.     

强碱性离子交换树脂再生新工艺的研究

用还原性的硫酸亚铁溶液作为再生剂，对吸附Cr^6 的强碱性离子交换树脂的再生机理进行了初步的探讨和再生工艺的研究，试验结果表明，用硫酸亚铁溶液作为再生剂，可以降低铬离子对树脂骨架的破坏，再生效率可以保持在0．85以上，再生工艺条件如下：再生剂硫酸亚铁溶液的浓度为0．5－1．0mol/L，用量为树脂体积的3－5倍，PH为1－2，流速为2－4m/h，再生温为25－45℃。     

固硫灰固化焦化废水处理外排污泥

采用机械力化学法活化循环流化床燃煤固硫灰,用于固化焦化废水处理外排污泥(CWT污泥)。探讨了固硫灰活化条件,并通过XRD和FTIR分析了固硫灰固化CWT污泥中重金属的机理。实验结果表明:当m(Ca O)∶m(Ca O+固硫灰)为20%、球磨频率为40 Hz、球磨时间为2 h时,养护28 d固硫灰固化体的平均抗压强度达到72.2 MPa;当污泥掺加量为50%(w)时,养护28 d含污泥固化体的抗压强度达到8.5 MPa,固化体浸出液中Pb2+和As5+的质量浓度分别为0.177 mg/L和0.013 mg/L,均远低于GB 5085.3—2007《危险废物鉴别标准浸出毒性鉴别》的规定限值。XRD和FTIR表征结果表明,在固硫灰活化过程中,混合体系水化生成了C—S—H凝胶、斜方钙沸石和钙矾石,可通过物理包裹、吸附及离子交换的形式实现CWT污泥中Pb2+和As5+的固化/稳定化。     

Modelling the effects of waste components on cement hydration

Ordinary Portland Cement (OPC) is often used for the solidification/stabilization (S/S) of waste containing heavy metals and salts. These waste components will precipitate in the form of insoluble compounds on to unreacted cement clinker grains preventing further hydration. In this study the long term effects of the presence of contaminants in solidified waste is examined by numerically simulating cement hydration after precipitation of metal salts on the surface of cement grains. A cement hydration model was extended in order to describe pore water composition and the effects of cement grain coating. Calculations were made and the strength development predicted by the model was found to agree qualitatively with experimental results found in literature. The complete model is useful in predicting the strength and leaching resistance of solidified products and developing solidification recipes based on cement.     

Assessment of the leaching of metallic elements in the technology of solidification in aqueous solution

Results are presented of experiments performed to optimize the solidification/stabilization system for metallic elements in aqueous solution. This system involves mixing cement and a solution of metallic elements in a conventional mixer: the paste thus obtained is transferred drop by drop into a recipient filled with an aqueous solution of NaOH at 20% by weight, in which it solidifies immediately. The separate use of chloride solutions of Li+, Cr3+, Pb2+ and Zn2+ makes it possible to obtain granules displaying various levels of compressive strength. Three different inertization matrices were used in the experiments, the first consisting solely of Portland cement, the second of Portland cement and a superplasticizer additive, and the third of Portland cement partially replaced with silica-fume and superplasticizer. The results of the tests performed showed a very low level of leaching into the alkaline solidification solution for Cr3+, the quantity leached being under 2% as against higher levels for the other metallic elements. For all the considered elements, the best results were obtained by using silica-fume in the inertization matrix.     

Solidification with water as a treatment method for air pollution control residues

The process of solidification with water was studied on air pollution control (APC) residues from incineration of refuse-derived fuel (RDF) regarding mechanical strength and leaching behaviour of solidified material. Factorial design in two levels was applied to investigate the impact of water addition, time, and temperature to mechanical strength of solidified material. Factors time and temperature, as well as the interaction between the addition of water and time significantly (alpha=0.05) influenced the mechanical strength of solidified material. The diffusion-leaching test NEN 7345 was performed to investigate if the leaching behaviour of elements from solidified material was determined by diffusion. Since it was found that leaching is not diffusion controlled, the long-term leaching behaviour was not assessed. However, the investigation showed that some of the studied components (Al, Hg, Mn, Pb, Si, and Zn) could be considerably demobilised by solidification with water. Concentrations of As, Cd, Co, Cu, Fe, and Ni were either below or not quite above the detection limits to be included in the analysis of leaching behaviour. The elements least demobilised by solidification were Cl, Cr, K, and Na.     

粉煤灰-粉煤灰合成沸石对Cs~+的固化

以电厂废弃物粉煤灰为原料、采用碱熔-水热法制备了粉煤灰合成A型沸石(以下简称沸石),再以沸石对溶液中的Cs+进行分离富集,最后在碱激发剂的作用下以粉煤灰和吸附后的沸石制得地聚合物固化体。对固化体的性能进行了评价,并探讨了固化机理。实验结果表明:在吸附温度25℃、初始Cs+质量浓度100 mg/L、固液比10.0 g/L的条件下,沸石对的Cs+的吸附率达98%,比粉煤灰提高了2倍以上;沸石掺量为20%~30%(w)时,固化体的抗压强度符合GB 14569.1—2011要求,固化体中Cs+的42 d浸出率和累计浸出分数均远优于GB 14569.1—2011限值,表现出优异的抗浸出性能。     

Immobilization of radioactive waste by cementation with purified kaolin clay

A study is undertaken to determine the waste immobilization performance of low-level wastes in cement-clay mixtures. Liquid low-level wastes are precipitated using chemical methods, followed by solidification in drums. Solidification is done using cementation processes. Long-term leaching rates of the radionuclides are used as indicators of immobilization performance of solidified waste forms. In addition to evaluating the effects of kaolin clay on the leaching properties of the cemented waste forms, the effect of addition of kaolin on the strength of the cemented waste form is also investigated. The long term leaching tests show that inclusion of kaolin in cement reduces the leaching rates of the radionuclides significantly. However, clay additions in excess of 15 wt.% causes a significant decrease in the hydrolytic stability of cemented waste form. It is found that the best waste isolation, without causing a loss in the mechanical strength, is obtained when the kaolin content in cement is 5%.     

Stabilization of chloro-organics using organophilic bentonite in a cement-blast furnace slag matrix.

The application of cement-based stabilisation/solidification treatment to organic-containing wastes is made difficult by the adverse effect of organics on cement hydration. The use of organophilic clays as pre-solidification adsorbents of the organic compounds can reduce this problem because of the high adsorption power of these clays and their compatibility with the cementitious matrix. This work presents an investigation of the effect on hydration kinetics, physico-mechanical properties and leaching behaviour of cement-based solidified waste forms containing 2-chlorophenol and 1-chloronapthalene adsorbed on organophilic bentonites. These were prepared by cation exchange with benzyldimethyloctadecylammonium chloride and trimethyloctadecylammonium chloride. The binder was a 30% pozzolanic cement, 70% granulated blast furnace slag mixture. Several binder-to-bentonite ratios and different concentrations of the organics on the bentonite were used. Kinetics of hydration were studied by measurement of chemically bound water and by means of thermal and calorimetric analyses. Microstructure and other physico-mechanical properties of the solidified forms were studied by means of mercury intrusion porosimetry, scanning electron microscopy and unconfined compressive strength measurement. Leaching was checked by two different leaching tests: one dynamic, on monolithic samples, and the other static, on powdered samples. This study indicates that the incorporation of the organic-loaded bentonite in the binder matrix causes modifications in the hardened samples by altering cement hydration. The effects of the two organic contaminants are differentiated.     

Municipal incineration bottom ash treatment using hydrothermal solidification

Solidification of municipal incineration bottom ash (MIBA) has been carried out using a hydrothermal processing method, in which the MIBA was first compacted in a mold at 5-20 MPa, and then hydrothermally cured in an autoclave under saturated steam pressure at 150-250 degrees C for 10-72 h. Experimental results showed that the tensile strength of the solidified body was greatly influenced by the addition of NaOH solution and fresh cement in the MIBA. The hydrothermal curing temperature and time exerted a significant influence on the development of tensile strength of solidified body. The strength development is speculated to be due primarily to the formation of 1.1 nm tobermorite. Laboratory leaching tests were conducted to determine the amount of heavy metals dissolved from the solidified bodies and the results showed that under the hydrothermal conditions of this study the leaching of heavy metals was very low. As such, the hydrothermal processing method may have a high potential for recycling MIBA.