钙镁离子对云南磷矿浮选的影响及回水处理

以云南晋宁、安宁和昆阳磷矿为研究对象,在浮选过程中添加钙镁离子,通过回收率、品位的变化研究其对浮选效果的影响.试验结果表明,当加入的钙镁离子达到一定浓度后,对晋宁和安宁磷矿正浮选有不同程度的影响,而对昆阳磷矿单一反浮选影响不大.同时,晋宁和安宁磷矿正浮选尾矿水钙镁离子的测定结果表明,正浮选尾矿水中的钙镁离子浓度为45 mg/L时不足以影响正浮选过程,正浮选尾矿水可直接返回正浮选;当正反浮选废水混合回用,钙镁离子离子浓度超过100 mg/L时,需处理去除.     

水质硬度对煤泥浮选的影响

用循环水和自来水作为浮选试验用水,用石膏和硫酸钾作为水质调整剂,通过实验室和工业试验,研究水质硬度对煤泥浮选的影响．结果表明：水质硬度是影响煤和黏土颗粒之间分散稳定性的关键因素．随着水质硬度的升高,浮选精煤灰分提高了1％～2％,但精煤产率没有明显变化．水质硬度小于35。DH时,水质硬度越高,煤和黏土颗粒之间的凝聚作用越强,精煤灰分越高;水质硬度大于35°DH时,这种凝聚作用不再增强,精煤灰分也不再提高．     

二价铁离子对零价铁还原硝基苯的影响

为了解地下水环境中铁离子对零价铁(zero valention)还原作用的影响,采用批次实验,研究不同质量浓度二价铁离子对ZVI还原硝基苯的影响,利用HPLC和GC-MS作为分析工具,观测反应过程中硝基苯的质量浓度,同时跟踪溶液中Fe2+、pH、ORP的变化.结果表明,有无Fe2+存在,硝基苯均可被ZVI还原为苯胺,Fe2+没有改变还原产物;溶液中投加Fe2+后,ZVI还原硝基苯的反应速率明显加快,溶液中Fe2+对于还原反应起促进作用;溶液中Fe2+对ZVI体系pH起缓冲作用,含有Fe2+的ZVI体系ORP下降明显.反应动力学分析表明,硝基苯的还原反应符合假一级动力学模型,表观速率常数kobs值随Fe2+质量浓度的升高而增加,Fe2+离子的存在有助于ZVI对硝基苯的还原.     

金属离子对发酵性丝孢酵母发酵产油脂的影响

通过摇瓶发酵．考察了不同浓度金属离子（Mg^2＋、Mn^2＋、Cu^2＋、Zn^2＋）对发酵性丝孢酵母（Trichosporon fermentans）发酵产油脂的影响，研究结果表明：培养基中添加适量的Mg^2＋、Cu^2＋、Zn^2＋有利于细胞积累油脂．但Mn^2＋对菌体生长及积累油脂不利。     

金属离子对发酵性丝孢酵母发酵产油脂的影响

通过摇瓶发酵,考察了不同浓度金属离子(Mg2+、Mn2+、Cu2+、Zn2+)对发酵性丝孢酵母(Trichosporon fermentans)发酵产油脂的影响,研究结果表明:培养基中添加适量的Mg2+、Cu2+、Zn2+有利于细胞积累油脂,但Mn2+对菌体生长及积累油脂不利。     

Determination of consolidation behaviour of clay slurries

The main objective of this study was to determine the consolidation behaviour of clay slurries.A finegrained clay with high consistency limits(W_L = 180%,w_P= 120%) was investigated using conventional oedometer and bench-top centrifuge tests.Results indicated that the slurry had an apparent preconsolidation(due to initial conditions,electrochemical interactions,tortuous drainage,and thixotropic strength) from e = 5.7 to e = 5.5 followed by virgin compression.Likewise,the low hydraulic conductivity(10~(-10)-10~(-12) m/s) was due to low porosity(small pore throats) and high tortuosity(long flow paths).Unlike consolidation of soils,the c_v and m_v decreased with increasing σ' but increased with increasing e and k.The data from the two tests correlated well in the range of σ' = 10-65 kPa,e = 5.5-3.86,k= 1.7 × 10~(-10)-5×10~(-11) m/s,F_c = 1-40 MN.New equations were developed to correlate the consolidation parameters(e,σ',k) with F_c.The deviation of k beyond 40 MN(e = 4.65) was due to deviation from the initial straight line portion of the settlement curve in the centrifuge test.     

Desulfurization of coal by an electrochemical-reduction flotation technique

The optimum conditions for sulfur removal from coal by electrochemical reduction flotation in an aqueous NaCI solution were determined from orthogonal experiments. The effect of electrolytic conditions on the desulfurization ratio was also studied.The electrochemical-reduction processed coal was examined by X-ray diffraction, Fourier transform infrared spectroscopy and wet chemical analysis. The results show that electrochemical reduction converts hydrophobic pyrite in Nantong coal into hydrophilic FeS and S2 and leads to an increase in the concentration of hydroxyl groups and aliphatic moieties and a corresponding decrease in carboxyl and carbonyl groups, which enhances the flotation desulfurization of the coal.     

加压溶气气浮法处理矿井水中悬浮物的研究

对加压溶气气浮法处理矿井水中悬浮物的处理效果进行了试验研究。研究结果表明,当悬浮物浓度小于500mg L时,反应时间为6-8min,溶气压力为0.30MPa,回流比为10-15%,分离负荷为5-7m3 m2·h,投加0.1-0.3mg L的表面添加剂后,处理后的水质可满足工业回用水要求。该工艺去除效率高,运行管理方便,占地少,投资省,投药量少,是一种经济实用可行的处理工艺。     

Advances in interaction mechanism of water (gas) on clay minerals in China

Dealing with large-scale deformations in soft-rock tunnels is a very important issue in soft-rock tunnel engineering. The mechanism of this large-scale deformation is closely related to the physical an...     

Determination of the desiccation behavior of clay slurries

The main objective of this study was to determine the desiccation behavior of clay slurries. A clay slurry with high water adsorption capacity(W_L = 180%,W_P 60%,W_s = 20) was used to determine the soil water characteristic curve(SWCC), shrinkage curve, and hydraulic conductivity. The last parameter was determined similar to the Instantaneous Profile Method using evaporation tests. Results indicated that the clay slurry had an air entry value(AEV) of 1000 kPa and a residual suction of 5000 kPa that occurred at the plastic limit and the shrinkage limit, respectively. The discrepancy between theoretical and measured shrinkage limit was due to the gradual increase in clay particle contact. Unlike soils, the saturated hydraulic conductivity varied by two orders of magnitude(4×10 ~10 m/s at 20 kPa to 3 x 10 ~12 m/s at AEV). The unsaturated k further decreased to 10 ~14 m/s at 6 x 10~4 kPa beyond which vapor flow took place.     

Prediction of operational parameters effect on coal flotation using artificial neural network

Artificial neural network procedures were used to predict the combustible value (i.e. 100-Ash) and combustible recovery of coal flotation concentrate in different operational conditions. The pulp density, pH, rotation rate, coal particle size, dosage of collector, frother and conditioner were used as inputs to the network. Feed-forward artificial neural networks with 5-30-2-1 and 7-10-3-1 arrangements were capable to estimate the combustible value and combustible recovery of coal flotation concentrate respectively as the outputs. Quite satisfactory correlations of 1 and 0.91 in training and testing stages for combustible value and of 1 and 0.95 in training and testing stages for combustible recovery prediction were achieved. The proposed neural network models can be used to determine the most advantageous operational conditions for the expected concentrate assay and recovery in the coal flotation process.     

Characteristics and genesis of clay minerals in the northern margin of the Qaidam Basin

In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency, characteristics of clay minerals from eleven clay rock samples from the northern margin of the Qaidam Basin were investigated using X-ray diffraction analysis, the Scanning Electron Microscope (SEM) and energy spectrum analysis. Clay mineral composition and distribution characteristics of the main hydrocarbon reservoirs, I.e., from the Jurassic and Paleogene-Neogene, were explored. We analyzed the main factors which affected these attributes. The results show that the major clay minerals in the northern margin are chlorite, kaolinite, illite, smectite and illite/smectite inter-stratified minerals, Illite is the most widely spread clay mineral in this area.Chlorite is mainly found in the entire Neogene and in shallow horizons of the Paleogene. Smectite is enriched in the shallow Paleogene-Neogene. There are large amounts of kaolinite and illite/smectite inter-stratified minerals in the Jurassic. The major factors affecting the different development of clay minerals in the region are properties of parent rocks, paleoclimate and paleowater media conditions,diagenesis transformation, tectonic and terrain conditions.     

改性膨润土吸附重金属离子

本文介绍了采用有机高分子使膨润土端面带有的正电荷为负电荷,从而增大了膨润土所带的负电荷总量和表面积.同时,研究了提高吸附重金属离子(Hg2 、Cr6 、Co2 )的性能.实验结果表明:改性的膨润土比未改性的膨润土对金属离子的吸附率提高近20个百分点.利用x射线衍射图证明膨润土端面改性是成功的,并解释了改性膨润土提高重金属离子吸附率的原因,利用改性的办法可能进一步扩大膨润土处理工业废水的应用.     

Process intensification of fine coal separation using two-stage flotation column

Flotation column is widely used as the separation equipment for fine mineral due to its high selectivity. However, this device may be unsuitable for the coarse particle flotation and has high handling ability. A two-stage flotation column with dimensions of 2 000 mm× 1 000 mm×4 000 mm was designed to enhance the column flotation process. The energy input was modified by adjusting the flow rate and the head of circulating pump. The flotation column was designed with low energy input in the first stage （speed flotation stage） to recover easy-to-float materials quickly, and high energy input in the second stage （recovery stage） to recover difficult-to-float minerals compulsorily. Contrast experiments on the throughput and coarse coal recovery of high ash coal from the Kailuan Mine were conducted using conventional single-stage flotation column and the two-stage flotation column. The results show that the combustible matter recovery of the two-stage flotation column is 5.25% higher than that of the conventional single-stage flotation column. However, the ash contents of clean coal for both columns are similar. Less coarse coals with low ash are obtained using the two-stage flotation column than that using the single-stage column flotation with the same handling ability. The two-stage flotation column process can enhance coal flotation compared with the conventional single-stage column flotation.     

Physical properties and ?lter cake structure of ?ne clean coal from flotation简

In order to improve the dewatering rate and the effect of fine clean coal (FCC), the advanced method of fine coal (−0.5 mm) dewatering and the correlated basic theory were investigated in this study. It was found that the dewatering by sleeve type press filter was an efficient way of FCC dewatering. On the other hand, the results also proved that particle size distribution, volatile matter, ash content, pore size distribution and specific surface area of coal particles of FCC samples, as well as viscosity and density of FCC slurry, were important parameters in determining the process of efficient dewatering. Especially, wet mass to dry mass, specific resistance of average mass, compressibility factor and microstructure of filter cake explained the reasons and mechanisms of fine clean coal efficient dewatering.     

碳化法原位成盐包膜提高CAC稳定性的研究

对无水氯化钙与液氨的反应产物的稳定性进行了研究,提出了改进ＣＡＣ稳定性新技术一碳化法原位成盐包膜技术。研究表明：碳化法原位成盐包膜可以较好地提高ＣＡＣ稳定性。包膜ＣＡＣ的最佳条件是：当ＣＡＣ呈膏状且不流动时通以流速为１２０ｍＬ／ｍｉｎ的ＣＯ２３－５ｍｉｎ对ＣＡＣ进行微粒包膜,经造粒后进行大颗粒二次包膜,二次膜后的ＣＡＣ的２５－３５℃范围可以较稳定存在,且包膜后的ＣＡＣ含氮量可以稳定在３１％以上。大     

壳聚糖/SiO_2杂化膜制备及其对铜离子吸附性能的研究

用硅偶联剂氨丙基三乙氧基硅烷(KH550)作为前躯体和交联剂,与壳聚糖通过溶胶-凝胶反应制备了壳聚糖/SiO2纳米杂化膜.用红外光谱对杂化膜进行表征,并研究杂化膜的溶胀性能、耐酸性能及不同的因素对杂化膜吸附重金属铜离子性能的影响.结果表明:红外光谱图显示杂化膜内有新键产生,引入了Si-O-Si结构.壳聚糖/SiO2纳米杂化膜溶胀性能降低,耐酸性能提高,吸附铜离子性能提高.当壳聚糖/SiO2纳米杂化膜中SiO2的质量分数为6.8%时杂化膜吸附铜离子性能最好.室温下溶液pH值为5、铜离子浓度为0.05 mol/L、时间为60 min时,杂化膜CSH1对铜离子有较好的吸附效果.     

Effects of sodium hexmetaphosphate on flotation separation of diaspore and kaolinite

1INTRODUCTION ThebauxiteinChinaismainlyofdiasporite type,withhighcontentofAl2O3butlowmassra tioofAl2O3toSiO2.Themainsiliceousminerals ofbauxitearekaolinite,illiteandpyrophyllite[1].Inordertoutilizethebauxiteeffectively,anewflotationdesilication Bayermethodwasdeveloped toproducealumina.Thepurposeofflotationdesil icationistoremovethesilicafromthebauxiteandtoincreasethemassratioofAl2O3toSiO2.Funda mentalresearchofreverseflotationdesilicationhas beenpaidmoreattentionduetoitsadvantageover…