法库县硬质高岭土矿初步浮选试验

法库县前新秋热液蚀变次流纹岩型硬质高岭土矿，属大型优质矿床。用十二胺做捕收剂，采用常规浮选工艺浮选微细粒和超微细粒高岭石和石英等矿物。经过一次粗选二次精选初步浮选试验，获得高岭土精矿：Ａｌ２Ｏ３含量３４．０６％，Ａｌ２Ｏ３回收率７０．５７％，产率３８．４０％。     

氟硅酸镁——水泥混凝土的多用途外加剂

<正> 氟硅酸镁可以改善混凝土和水泥制品的许多性能。它是良好的促硬剂,国外水泥促硬剂一般要含有1%氟硅酸镁。结硬和干燥的混凝土表面用它处理后,可增加耐磨性,减少起尘;用3～7%的氟硅酸镁溶液处理后,再用12～20%的氟硅酸铝溶液处理,可抑制混凝土的裂变剥蚀。氟硅酸镁适合做增     

磷矿渣掺合料性能试验研究

对磷矿渣掺合料的性能进行测试,结果表明,磷矿渣具有显著的缓凝效应；硫酸钠和氢氧化钙复掺效果优于单掺,掺量为胶凝材料总量的4％时,磷矿渣活性的激发效果较好:掺入磷矿渣后混凝土的初始坍落度和扩展度分别提高了12％-24％和15％～ 34％,1h和2h的坍落度损失分别小于14％和26％,磷矿渣掺合料显著改善了新拌混凝土工作性能；磷矿渣掺量为50％时,混凝土60、90 d抗压强度分别增加了6.5％和12.6％.     

风化花岗岩砂-磷矿渣-石灰加气混凝土

为解决三峡库区移民工程墙材问题,武汉工业大学马保国副教授等针对当地资源情况,对风化花岗岩砂－磷矿渣－石灰加气混凝土的生产工艺参数和微观结构进行了研究,利用风化砂生产加气混凝土在国内外均属首次。结果表明,其适宜的配合比范围为：风化砂５０％～６０％,磷矿渣１０％～１５％,石灰１８％～２０％,水泥３％～６％,石膏４％,外掺激发剂０．６％～０．９％、铝粉膏０．０７％,水灰比０．６２～０．６８,钙硅比０．７０～０．８０。用此配方生产的加气混凝土质量达到国家标准。秭归加气混凝土厂每年向三峡移民工程提供６万ｍ…     

混凝土表面增强处理对抗冲蚀磨损性能的影响

兰新铁路第二双线(新疆段)穿越五大风区。风区地段,强风携带的砂粒对兰新铁路混凝土结构产生严重的冲蚀磨损,造成混凝土结构耐久性的降低。选用JNF型抗冻型硅溶胶,氟硅酸镁+氟硅酸铝和沃尔VL-M1高效混凝土密封固化剂对混凝土表面进行了处理。并分别在处理试样上涂装了水性硅丙乳液、环氧树脂+聚氨酯和PPG聚氨酯涂料作为风蚀防护层。试验结果表明:混凝土的基底处理均在一定程度上提高了其表面耐磨性,而其中以氟硅酸镁+氟硅酸铝处理的表面耐磨性提高最多;在同种表面处理时,环氧树脂+聚氨酯涂料的抗冲蚀性能最好,PPG涂料次之,水性硅丙乳液最差;在不同表面处理后,氟硅酸镁+氟硅酸铝溶液表面处理的试块,涂料的抗冲蚀性能亦最好。     

氟硅酸盐对混凝土性能的影响

通过研究氟硅酸盐对混凝土凝结时间、工作性、抗渗性能的影响,探讨氟硅酸盐对于综合改善混凝土耐久性的可行性。结果表明:掺入适量氟硅酸盐,可有效延长混凝土凝结时间;掺入0.5%氟硅酸镁,混凝土具备最佳的工作性能;掺氟硅酸盐外加剂混凝土具有良好的抗渗性能;综合改善混凝土耐久性的氟硅酸盐最佳掺量为0.5%的氟硅酸镁。     

水化温升抑制技术在地下车站结构混凝土中的应用研究

为降低地下车站结构混凝土温度收缩开裂风险,试验研究了基准与掺加水化温升抑制剂C35P8混凝土的水化放热、强度、凝结时间等性能变化规律,结果表明,水化温升抑制剂明显降低早期水化放热,掺量增加,抑制效果越显著.当掺量0.2％时,1d绝热温升降低率57.1％,7d绝热温升接近基准,终凝时间推迟2.49h,3d强度降低17.7％,28d达到基准的100.4％,构件试验最高温升降低5.9℃,4d均降温速率减小24.9％,控温效果良好,为该产品在实体结构规模化应用提供参考.     

太阳能光伏玻璃原料用砂的提纯试验研究

在对陕西某地的石英岩矿进行工艺矿物分析基础上,采用磨矿、分级、磁选、擦洗、浮选等工艺进行选矿提纯研究.试验结果表明：采用磨矿—分级—磁选—擦洗—浮选组合工艺后,可获得石英精砂SiO2 99.89％、Al2O30.017％、Fe2O30.0054％、TiO20.01％,达到了光伏玻璃用砂的要求.     

石墨矿尾矿制备路面砖面层的试验研究

简单介绍了石墨矿尾矿的组成及物理性质,石墨矿尾矿砂浆制备及性能研究,石墨矿尾矿砂浆与胶磷矿尾矿基层复合后的力学性能,混凝土路面砖的性能测试等方面。利用胶磷矿尾矿作为基层骨料,石墨尾矿砂代替天然砂制备水泥砂浆附在道路砖面层,以及普通硅酸盐水泥（32．5R）作为胶凝材料制备彩色路面砖。砖的面层厚度8～10mm,原料配合比：灰砂比0．33（水泥含量占原料25％）、水灰比0．18、减水剂占水泥的0．8％、颜料占原料的5％,经砂浆制备、基层与面层复合、振动成型、抹平表面、标准养护等一系列工艺步骤制成彩色路面砖。经测定,该砖3d抗压强度达11MPa,7d抗压强度达17MPa,28d抗压强度达30MPa,符合路面砖国家标准,为矿山企业综合利用胶磷矿尾矿资源和石墨矿尾矿资源提供了可靠的技术依据。     

微气泡旋流气浮选设备的研究与应用

针对目前注聚油田污水处理流程存在的设备脏堵严重、处理不达标的问题,提出利用微气泡旋流气浮选设备进行含聚污水的处理。文中对微气泡旋流气浮选设备的原理、工艺流程进行阐述,通过联调,设备处理效果良好,除油率平均为86.12％,COD平均去除率20％,悬浮物去除率为94.7％,罐内浮选出污油泥自动导出,避免了设备的堵塞。     

Fluorine pollution in the marmara region,Turkey. Production methods for fluorine removal and recovery

The importance of the removal and recovery of fluorine from Turkish fertilizer plant effluents has been emphasized. Even though the economic evaluation of the processes developed are not based on capital and operating costs for the processes there are strong economic incentives to adopt recovery apart from clear environmental needs. Selection of the methods for the removal of fluorine through production processes specifically the dependence of the choice of waste treatment process on available H₂SiF₆ concentration have been discussed. The production of acid grade calcium fluoride and sodium fluosilicate from waste fluosilicic acid solutions were studied.The optimum process conditions were determined. It has been found that it is possible to produce these industrially valuable fluorine compounds from 2.5 to 4.5% H₂SiF₆ containing waste waters and in appropriate conditions both processes are effective in removing 90–95% of the fluorine present in waste fluosilicic acid solutions. It has been shown that for the production of acid grade calcium fluoride and sodium fluosilicate the P₂O₅ content of waste fluosilicic acid solutions should be < 250 mg P₂O₅ I⁻¹ and 300 mg P₂O₅ I⁻¹ respectively. It has been suggested to make pilot plant studies for the industrial application of the processes.     

Inhibition of calcite crystal growth by polyphosphates

The inhibition of calcite crystal growth by pyrophosphate (P(2)O(7)(4-)), tripolyphosphate (P(3)O(10)(5-)), hexametaphosphate (P(6)O(18)(6-)) and binary-polyphosphate blends in calcite-seeded solutions was investigated with various solution compositions using a pH-stat system. In a single polyphosphate system, tripolyphosphate was found to be the strongest inhibitor, followed by pyrophosphate and hexametaphosphate. The inhibition can be explained by the adsorption of polyphosphates on the calcite surface conforming to a simple Langmuir adsorption model. Through a detailed speciation analysis, CaP(2)O(7)(2-) and CaP(3)O(10)(3-) were found to be the primary species of pyrophosphate and tripolyphosphate responsible for adsorption of phosphate on the calcite surface, while the responsible species for hexametaphosphate could not be determined because of a lack of published stability constants. By comparing the equilibrium constants for the adsorption reaction, the inhibitory capabilities of polyphosphates are about two orders of magnitude greater than that of orthophosphate. In binary-polyphosphate systems, the inhibition of calcite crystal growth can be described by a competitive Langmuir adsorption model using the stability constants derived from single solute systems. The inhibitory behavior of commercially available phosphate blends that are marketed to prevent calcite scale formation were demonstrated to be similar to those of laboratory-prepared blends with the same chemical composition.     

Inhibition of calcium phosphate precipitation under environmentally-relevant conditions

Precipitation of Ca phosphates plays an important role in controlling P activity and availability in environmental systems. The purpose of this study was to determine inhibitory effects on Ca phosphate precipitation by Mg(2+), SO(4)(2-), CO(3)(2-), humic acid, oxalic acid, biogenic Si, and Si-rich soil clay commonly found in soils, sediments, and waste streams. Precipitation rates were determined by measuring decrease of P concentration in solutions during the first 60 min; and precipitated solid phases identified using X-ray diffraction and electron microscopy. Poorly-crystalline hydroxyapatite (HAP: Ca(5)(PO(4))(3)OH) formed in control solutions over the experiment period of 24 h, following a second-order dependence on P concentration. Humic acid and Mg(2+) significantly inhibited formation of HAP, allowing formation of a more soluble amorphous Ca phosphate phase (ACP), and thus reducing the precipitation rate constants by 94-96%. Inhibition caused by Mg(2+) results from its incorporation into Ca phosphate precipitates, preventing formation of a well-crystalline phase. Humic acid likely suppressed Ca phosphate precipitation by adsorbing onto the newly-formed nuclei. Presence of oxalic acid resulted in almost complete inhibition of HAP precipitation due to preemptive Ca-oxalate formation. Carbonate substituted for phosphate, decreasing the crystallinity of HAP and thus reducing precipitation rate constant by 44%. Sulfate and Si-rich solids had less impact on formation of HAP; while they reduced precipitation in the early stage, they did not differ from the control after 24 h. Results indicate that components (e.g., Mg(2+), humic acid) producing relatively soluble ACP are more likely to reduce P stability and precipitation rate of Ca phosphate in soils and sediments than are components (e.g., SO(4)(2-), Si) that have less effect on the crystallinity.     

A/O法与BAF联合工艺处理炼油生产废水

采用A/O与BAF联用工艺处理高浓度炼油生产废水,处理水量为300 m3/h。采用浮动环流收油器和涡凹CAF二级气浮处理系统对含油污染物进行回收。该系统无需外加压力,处理成本低,经二级气浮处理后对油类污染物的回收率达到96.7%。监测结果表明,对COD、氨氮、硫化物和石油类的去除率分别为96.1%、94.3%、77%和96.7%,出水水质满足《污水综合排放标准(》GB 8978—1996)中第二类污染物最高允许排放浓度一级标准,废水处理电耗为1.59 kW.h/m3。     

广西某低品位粉石英矿反浮选试验研究

广西某地粉石英矿是目前区内发现的储量最大的粉石英矿床。通过对样品分级后获得的-0.045mm粒级产品进行反浮选除杂,可获得较高纯度的石英精矿产品。影响该矿反浮选效果的主要因素有矿浆的pH值、分散剂的用量、捕收剂的种类与用量。通过正交试验,获得最佳条件组合：硫酸用量4 000g/t,水玻璃用量1 000g/t,燃料油用量600g/t,新药H1A用量200g/t。当试验样品SiO2含量94.32%、Al2O3含量2.15%,经过反浮选除杂,可获得细度-0.045mm、精矿产率82.87%、SiO2含量98.99%、Al2O3含量0.19%的粉石英浮选精矿。     

织金含稀土白云质磷块岩物质组成及稀土元素特征

选择贵州织金新华戈仲伍地区含稀土白云质磷块岩为研究对象,研究其矿物组成、化学成分、微量元素、稀土元素等特征。矿石主要矿物为白云石、氟磷灰石、石英等。矿石P2O5平均含量20.18%,主要稀土为钇（Y2O3）、镧（La2O3）、钕（Nd2O3）、铈（CeO2）,占稀土总量的84.51%～85.50%。矿石中P2O5和稀土元素含量均随风化程度加深而增加。本研究为该矿的综合开发利用提供基础资料。     

Aluminium speciation in forest soil solution--modelling the contribution of low molecular weight organic acids.

The concentrations of Al bound to identified low molecular weight organic acids (LMWOAs), phosphate and humic compounds in soil solutions (O1, O2, E, B1 and B2 horizons) from Fennoscandinavian coniferous forest soils were calculated. Two models were evaluated: WHAM (Winderemere Humic Aqueous Model) and a model treating the natural organic acids as monoprotic. The WHAM model was calibrated to find an average charge balance of unity, and then used for Al speciation. This was achieved considering approximately 80% of the natural fulvic acid to be 'active'. For the monoprotic model, constants obtained from previous fitting of soil solution data were used and the model was calibrated using acid/base titrations. The modelling confirms that the low molecular weight acids are important complex formers, binding on average 11-42% (O), 19-20% (E), and 0-30% (B) of the total Al in solution depending on the model used. The monoprotic model yielded higher concentrations than WHAM. Both models predicted that the major part of Al in solution was organically complexed to humic substances and LMWOAs, which was consistent with analytical values of 'quickly reacting' Al (monomenc inorganic forms; 12-14% of Al(tot) on average in the E and B1 solutions). Both models could predict the magnitude of the analytical values (RMSD = 4-5 microM). On average the WHAM model showed a better fit for the E horizon solutions and the monoprotic model for the upper B horizon. The pH dependence of the low molecular weight fraction of Al was modelled in the pH range 3-5.5 for a 'typical' O1 and E solution assuming no other changes in soil solution composition. The extrapolation showed that the models had a different pH dependence. The concentration of Al bound to LMWOAs in WHAM decreased with higher pH while the opposite was seen for the monoprotic model. Also the influence of the concentration of total Al in solution was modelled. The models showed similar trends but for the 'typical' O1 horizon sample the monoprotic model yielded higher concentrations of Al bound to LMWOAs than WHAM.     

外加剂对硫氧镁水泥力学性能的影响及水化机理分析

对比了柠檬酸、磷酸二氢钠、乙二胺四乙酸3种外加剂掺量分别为0、0.5%、1.0%、1.5%(以氧化镁的质量计)时对硫氧镁水泥强度的影响,并通过XRD、XPS、FTIR、SEM对加入外加剂后硫氧镁水泥的水化机理进行了分析。结果表明:3种外加剂中,柠檬酸对硫氧镁水泥的改性效果最好;掺加1.5%柠檬酸的硫氧镁水泥28 d抗压强度达到73.33 MPa,较未掺加外加剂的试块提高了56.5%;加入外加剂后水化产物中出现了针状的5Mg(OH)2·MgSO4·7H2O相(517相)晶体,可以很好的改善硫氧镁水泥的力学性能;外加剂的加入阻碍了活性MgO表面Mg(OH)2的生成,促进了碱式硫酸镁复盐的形成。     

Assessment and management of risks arising from exposure to cadmium in fertilisers--II

A preliminary, illustrative human health risk assessment of exposure to cadmium in phosphate fertilisers was performed using typical UK data and a protocol previously developed for application by individual Member States in the European Union. The risk assessment indicated that the for the most pessimistic population exposures characterised by both extreme (97th percentile) cereal and potato consumption and high susceptibility to cadmium uptake, the estimated dose was under the WHO Provisional Tolerable Weekly Intake (PTWI) for fertiliser cadmium concentrations ranging from 15 to 100 mg Cd/kg P2O5 applied over 100 years. However, the low margin of safety for high risk groups and the uncertainties inherent in the overall risk assessment suggested that a prudent risk management strategy would involve maintenance of low levels of cadmium in fertilisers and/or conditions that permitted low accumulation of cadmium in soils. On this basis, two main risk reduction measures were developed and assessed: (a) imposition of limits on cadmium concentration in fertilisers; and (b) imposition of charges on levels of cadmium in phosphate fertilisers. An assessment of the economic impact of these risk reduction measures indicated that, at all price elasticities, the most significant impact in terms of changes in demand and changes in consumer expenditure on phosphate fertilisers will be seen with cadmium charges where no thresholds are defined. The impact on the consumer (i.e. farmer) will be an increase in spending of approximately US $4000 per year, which is considered significant, accompanied by a decrease in demand above 20%. If a threshold is set at 60 mg Cd/kg P2O5, the impact is significantly reduced, but stays relatively high compared to the other options. The analysis also indicates that the use of low-cadmium rock is the low cost option. At a likely rock price increase of approximately 5% and assuming a likely price elasticity of -0.2, the yearly costs to farmers will be approximately US $82 which is considered a minimal impact. In the worst case scenario (elasticity of -0.6 and a 10% increase in rock prices), the increase in spending by farmers will be of 3.9% or US $221 which is also considered to represent a minimal impact. At similar price elasticities, the use of decadmation technologies is predicted to be more costly than the use of low-cadmium rock but this option can still be considered as having a minimal impact on the consumer (increase in expenditure of 1.9-13.3% or US $106-748).     

Field assessment of lead immobilization in a contaminated soil after phosphate application

A pilot-scale field demonstration was conducted at a Pb-contaminated site to assess the effectiveness of Pb immobilization using P amendments. The test site was contaminated by past battery recycling activities, with average soil Pb concentration of 1.16%. Phosphate amendments were applied at a 4.0 molar ratio of P/Pb with three treatments: T1, 100% P from H(3)PO(4); T2, 50% from H(3)PO(4)+50% from Ca(H(2)PO(4))(2); and T3, 50% from H(3)PO(4)+5% phosphate rock. Soil samples were collected and characterized 220 days after P application. Surface soil pH was reduced from 6.45 to 5.05 in T1, to 5.22 in T2, and to 5.71 in T3. Phosphate treatments effectively transformed up to 60% of total soil Pb from the non-residual fraction (sum of water soluble and exchangeable, carbonate, Fe-Mn oxide, and organic fractions) to the residual fraction relative to the control. In addition, P treatments reduced Toxicity Characteristic Leaching Procedure (TCLP) Pb from 82 mg l(-1) to below EPA's regulatory level of 5 mg l(-1) in the surface soil. Scanning electron microscopy-energy dispersive X-ray elemental analysis and X-ray diffraction analysis indicated formation of insoluble chloropyromorphite [Pb(5)(PO(4))(3)Cl] mineral in the P-treated soils. Although H(3)PO(4) is necessary to dissolve meta-stable Pb in soil for further lead immobilization, it should be used with caution due to its potential secondary contamination. A mixture of H(3)PO(4) and Ca(H(2)PO(4))(2) or phosphate rock was effective in immobilizing Pb with minimum adverse impacts associated with pH reduction.