甲萘胺浮选铝硅酸盐矿研究

研究了甲萘胺对叶蜡石、伊利石和高岭石的浮选行为。结果表明 ,甲萘胺对叶蜡石的回收率超过 98%,对伊利石和高岭石的捕收力相对较弱。矿浆pH值对叶蜡石和高岭石的回收率影响较小。在酸性及碱性条件下 ,伊利石的回收率下降。酸性矿浆中 ,捕收剂通过静电引力吸附在矿粒表面 ;碱性矿浆中 ,捕收剂主要通过氢键吸附在矿粒表面。红外吸收光谱表明 ,三种矿物表面均存在有 OH ;在一个较宽的pH值范围内 ,三种铝硅酸盐矿浆的zeta电位均为负值 ,表明矿粒表面荷负电。

Comparative studies on flotation of aluminosilicate minerals with Gemini cationic surfactants BDDA and EDDA

Gemini quaternary ammonium salt surfactants, butane-a, co-bis（dimethyl dodeculammonium bromide） （BDDA） ethane-a, fl-bis（dimethyl dodeculammonium bromide） （EDDA） were adopted to comparatively study the flotation behaviors of kaolinite, pyrophyllite and illite. It was found that three silicate minerals all exhibited good floatability with Gemini cationic surfactants as collectors over a wide pH range, while BDDA showed a stronger collecting power than EDDA. FTIR spectra and zeta potential analysis indicated that the mechanism of adsorption of Gemini collector molecules on three silicate minerals surfaces was almost identical for the electronic attraction and hydrogen bonds effect. The theoretically obtained results of density functional theory （DFT） at B3LYP/6-31G （d） level demonstrated the stronger collecting power of BDDA presented in the floatation test and zeta potential measurement.

用烧结法处理霞石物料时其钠钾比对铝碱提取率的影响

用高压预处理调整矿样组成，使之铝铁含量保持不变，仅是ｋ２Ｏ／Ｒ２Ｏ比有所差异，用高温差热分析及烧成溶出试验等研究手段，确定了矿样ｋ２Ｏ／Ｒ２Ｏ比对碱质铝硅酸盐物料烧成性能的影响—ｋ２Ｏ／Ｒ２Ｏ高的物料须于更高的温度下烧成，且所获熟料之铝溶出率会有所下降。此外，还确定了熟料溶出时钠与钾在固液相间的分布与熟料的ｋ２Ｏ／Ｒ２Ｏ有关：富钠料之溶出渣中钾相对富集；富钾料之溶出渣中钾相对贫化。故此，以苏打作为补碱配制生料。

Effect of Perched Water Tables on Aluminosilicate Stability and Soil Genesis

The mineral stability and solute activities of soil solution extracted from selected horizons of seven studied pedons of Alfisols in Kentucky, USA, and the relationship between distribution of iron-manganese concretions and the restrictive layers were investigated. The results showed that the genesis and development of these soils and mineral weathering trends were strongly influenced by the depth of bedrock and the presence of perched water tables at lithic (limestone) interfaces due to the dissolution and buffering effect of limestone bedrock. The extractable Mg/Ca ratio as depth function and soil depth above bedrock could be used as indices of weathering and degree of soil development. Maximum iron-manganese concretion accumulation was found to occur in the horizon overlying clay horizon (>40% clay) with a sharp increase in clay content (>10%), which suggested that zones of Fe-Mn concretion accumulation in soils of the Inner Bluegrass Region appeared to be a sensitive genetic indicator of argillic horizons with restrictive permeability.

Influence of silicate anions structure on desilication in silicate-bearing sodium aluminate solution

The structural changes of silicate anions in the desilication process with the addition of calcium hydrate alumino-carbonate were studied by measuring Raman spectra, infrared spectra and corresponding second derivative spectra. The results show that the desilication ratio in the solution prepared by the addition of sodium silicate(solution-SS) is much greater than that in the solution by the addition of green liquor(solution-GL), and low alumina concentration in the sodium aluminate solutions facilitates the desilication process. It is also shown that alumino-silicate anions in the solution-GL, and Q^3 polymeric silicate anions in solution-SS are predominant, respectively. In addition, increasing the concentration of silica favors respectively the formation of the alumino-silicate or the Q^3 silicate anions in the solution-GL or the solution-SS. Therefore, it can be inferred that the low desilication ratio in the silicate-bearing aluminate solution is mainly attributed to the existence of alumino-silicate anions.

Iron Activation of Natural Aluminosilicates to Remove Arsenic from Groundwater

Low-cost adsorbents constituted by Fe-modified-aluminosilicates （laminar and zeolite type minerals） were developed and characterized to be used in the arsenic removal from groundwater. Iron activation was carried out ＂in situ＂ by the synthesis and deposition of mesoporous ferrihydrite. Natural iron-rich aluminosilicate was used as reference. All samples were characterized by X-ray diffraction, Raman spectroscopy, BET N2-adsorption, SEM-EDS microscopy and ICP chemical analysis. Experimental results of arsenic sorption showed that iron-poor raw materials were not active, unlike iron activated samples. The iron loading in all activated samples was below 5% （expressed as Fe203）, whereas the removal capacity of these samples reaches between 200-700 gg of As by g of adsorbent, after reusing between 17 cycles and 70 cycles up to adsorbent saturation. Differences can be associated to mineral structure and to the surface charge modification by iron deposition, affecting the attraction of the As-oxoanion. On the basis of low-cost raw materials, the easy chemical process for activation shows that these materials are potentially attractive for As（V） removal. Likewise, the activation of clay minerals, with natural high content of iron, seems to be a good strategy to enhance the arsenic adsorption ability and consequently the useful life of the adsorbent.