低品位磷矿制取磷酸试验研究

随着世界磷矿资源日渐枯竭,低品位磷矿的开发利用显得非常迫切.本研究采用硝酸分解低品位磷矿,以磷矿中P2O5的浸取率为指标,考察了硝酸的质量分数、酸比、反应温度、反应时间的影响,从而确定了硝酸分解低品位磷矿的最佳工艺条件为：硝酸质量分数29%、酸比8、反应温度60℃、反应时间45 min;在此最佳条件下,对磷矿P2O5的浸取率为98.1%;而且通过扫描电镜观察了不同反应时间下磷矿颗粒表面的形貌特征的变化.实验结果为两步法分解低品位磷矿制取磷酸并联产硫酸钙晶须的研究和可行性论证提供了基础数据.     

空气氧化软锰矿浸出液中Fe2+的动力学研究

利用空气氧化软锰矿浆烟气脱硫浸出液中的Fe2+,研究了Fe2+浓度、氧分压、氢离子浓度和温度对空气氧化Fe2+的反应速率的影响。结果表明,空气对Fe2+的氧化速率随Fe2+浓度、氧分压和温度的增加而加快,随氢离子浓度的增加而减小。动力学研究结果表明,空气氧化Fe2+的反应对Fe2+浓度为2级,对氧分压为1级,对氢离子浓度为-1级,反应的活化能Ea为101.4308kJ/mol,指前因子A0为2.48×1014s-1。     

城市规划专业低年级教学改革的探索

多年来城市规划专业低年级的教学等同于建筑学专业低年级的教学,造成了学生对高年级城市规划专业课阶段的学习难以适应。针对这一问题的根源,分析了城市规划与建筑学专业的不同特点,提出了城市规化专业低年级教学改革的措施,并结合教学实践提出了切实可行的教学方法。     

某中低品位钾长石无氟浮选试验研究

采用无氟浮选工艺对低品位钾长石矿进行了浮选试验研究,试验结果表明,采用磨矿-沉降脱泥-一粗一精-强磁选的选矿工艺流程,在磨矿细度为-0.074mm含量占50%,粗选pH为4,油胺与石油磺酸钠用量分别为800g/t、1600g/t时,可获得产率59%,K2O+Na2O品位为12.55%的长石产品,同时可获得产率为19.94%,SiO2品位为97.12%石英产品。此选矿工艺为该长石资源的综合利用提供了参考。     

BX型强磁选机分选白云鄂博低品位铁矿石试验研究

针对白云鄂博低品位铁矿石资源利用率低、选矿成本高等问题,在系统研究其矿石性质的基础上,采用BX型强磁选机进行磁选工艺试验研究。结果表明,原矿石TFe品位16.52%,通过干磁抛尾—两段磨矿—三段选别的工艺流程,可获得产率16.54%、TFe品位65.31%、TFe回收率65.39%、S、P含量分别为0.36%和0.07%的铁精矿。研究结果可为该低品位铁矿石的高效利用提供技术支持。     

福建某低品位金矿新型浸金剂浸金试验

福建某斑岩型金矿品位低、规模大,金主要以自然金形式存在,可见金的粒度较粗,为高效利用该低品位金矿,开展新型浸金剂金蝉全泥浸出试验和柱浸试验,结果表明：全泥浸出在磨矿细度为-0.074 mm占80%、矿浆浓度25%、加石灰调pH 值11.0左右、初始金蝉浓度为500 mg/L和过程中控制金蝉浓度不小于300 mg/L条件下浸出20 h,金的浸出率为93.43%,金蝉耗量为1.02 kg/t;柱浸在矿石粒度为-30 mm条件下喷淋浸出23天,金累计浸出率和金蝉累计耗量分别为86.54%和1.22 kg/t。     

Galena-pyrolusite co-extraction in sodium chloride solution and its electrochemical analysis

The co-extraction behavior of galena-pyrolusite in a sodium chloride solution and the electrochemical mechanism of this process were investigated, and some factors affecting the leaching rate of Pb and Mn were optimized. The results show that all the factors such as the concentration of NaCl, HCl and pyrolusite ore, reaction time, temperature, adding times of HCl, affect the leaching rate of Pb. The main affecting factors are the concentration of NaCl, reaction time and temperature. The Tafel polarization curves and EIS plots of the galena and pyrolusite in the NaCl solution demonstrate that during the oxidation process of galena mineral electrode, film forms on the galena surface, which prevents galena from deeper oxidation. However, the film resistance can be greatly reduced in the presence of sodium chloride, thus promoting the reaction rate of galena.     

Preparation of boric acid from low-grade ascharite and recovery of magnesium sulfate

Boric acid and kieserite were prepared from low-grade ascharite by sulfuric acid method. This method results in the recovery of 71.06% and 45.03% for boric acid and kieserite, respectively. Meanwhile, the boric acid was precipitated from the filtrate at low temperature and the solution was recycled without discharging waste liquid in the whole process. The influence of amount of sulfuric acid, mass fraction of sulfuric acid, reaction temperature and reaction time on the leaching rate of boric acid were studied. The results show that the leaching rate of boric acid reaches 93.80% under the following conditions: the amount of sulfuric acid is 85% of theoretical dosage; the mass fraction of sulfuric acid is 25%; reaction temperature is 95 ℃; and the reaction time is 100 min. Meanwhile, the effects of mass fraction of magnesium sulfate, crystallization temperature and crystallization time on the crystallization of kieserite were investigated and the optimal crystallization conditions are obtained: the mass fraction of magnesium sulfate is 28%; the crystallization temperature is 180 ℃ and the crystallization time is 4 h.     

搅拌强度对软锰矿浆湿法脱硫反应的影响

考察在不同搅拌强度下SO2的脱硫率及锰离子浸出率，在低转速范围，溶液中脱硫反应主要以MnO2和SO2为主，基产物主要为硫酸锰。在高转速范围，由于溶液中溶解氧浓度增大，脱硫反应则为在Mn^2 、Fe^2 催化下，水吸收SO2脱硫和MnO2与SO2氧化脱硫反应并存，其产物为硫酸锰和稀硫酸的混合物。     

软锰矿、菱锰矿吸收烧结烟气中的SO2制取硫酸锰

现代钢铁联合企业的高炉-转炉流程是铁-煤化工过程,针对该流程中烧结工序排放含二氧化硫烟气的特点,采用软锰矿、菱锰矿脱硫制取硫酸锰.采用菱锰矿调节和控制矿浆的pH值,利用软锰矿中MnO2的氧化性和SO2的还原性,用软锰矿矿浆在填料吸收塔内进行脱硫试验.试验结果表明:二氧化硫的吸收率在95%以上,该工艺还具有湿法除尘的特性,对烟尘的吸收率达90%以上,且副产品硫酸锰的质量能达到工业级,是一种真正实现"综合治理、变废为宝"的脱硫新技术.