基于内膜解耦控制的选煤厂浮选智能加药控制研究

为改善煤泥浮选性能,提出一种内膜解耦控制方法。针对浮选过程多变量特点,将解耦控制和内膜控制结合,对浮选过程加药量进行优化,以提高系统响应速度和浮选性能。为评估所提方案,在选煤厂浮选加药实际生产场景中,使用该方法进行加药优化,验证了该方法的有效性。结果表明,该方法在控制浮选生产稳定和模型失配方面更具优势。     

改进浮选药剂制度 提高浮选精煤产率

吕家坨矿选煤厂浮选加药系统存在加药精确度差、药剂分散效果差、加药调整难等问题,通过增设浮选药剂乳化器和转子流量计等设备,有效提高了药剂分散效果,加药精确可调,浮选系统精煤产率提高3.5%,浮选药剂消耗降低5.1%,取得了较好的经济效益。     

连续式高效节能梯级恒温浮选加药装置关键技术研究

运用自适应神经模糊控制原理,在参考传统浮选加药恒温设备的基础上,设计出了一款适应性更强、精度更高、方便灵活、移动式的高效节能梯级恒温浮选加药装置,该装置不用上位机电脑,能自动连续混加药,加热速度快,恒温效果好,加药过程药剂定常流动,操作人性化,运行成本低,还可以节约能源,提高浮选指标.     

模糊自整定PID控制方案在自动加药系统中的应用

在选矿工艺中,加药过程是影响选矿品质的重要因素,传统浮选加药主要采用人工加药或定量加药方式,其缺点是误差大、效率低和成本高。因此,提出一种模糊自整定PID控制方案,对加药过程进行自动控制。投产后,运行稳定,效果良好。     

新巨龙选煤厂降低浮选药耗的措施

分析了新巨龙选煤厂主要存在药剂与煤泥作用时间短、浮选药剂捕收性能差和浮选加药不可视等问题。针对以上问题,通过增加加药设施和加药点,延长药剂与煤泥的作用时间;根据煤泥性质,选择合适的捕收剂;增加可视化浮选加药槽,实现药剂添加可视化等措施对选煤厂进行改造。改造完成后,入浮煤泥和浮选药剂得到充分混合,提高了入浮煤泥的矿化效果;浮选加药装置的可视化便于浮选司机根据浮选效果及时调整药剂添加量。选煤厂浮选药耗由原来的0．34kg／t降至0．27kg／t,浮选精煤抽出率由68％提高至76％,有时甚至达到80％以上;捕收剂和起泡剂的质量比由原来的12：1提高至（18～20）：1;浮选精煤泡沫易碎、浓度高,加压过滤机排料周期维持在100S左右;节省药剂费用275．7万元。     

对浮选过程自动化的探讨

介绍了浮选工艺参数对分选效果的影响,提出浮选工艺参数自动化技术,从入浮矿浆浓度测控、自动加药、浮选机液位高度控制和药剂罐液位控制等方面阐述了浮选参数自动控制的意义,并建议加大推广浮选参数自动控制的力度。     

选煤厂煤泥浮选自动加药装置的研究进展

介绍了选煤厂煤泥浮选工艺中浮选自动加药装置的组成、控制原理和主要功能(浮选药剂的过滤、输送、计量、添加等),指出煤泥浮选效果受多个因素影响，需要根据选煤厂实际情况，具体问题具体分析，设计出适合现场工况的浮选自动加药装置。     

经坊选煤厂浮选预处理系统的改造

针对经坊选煤厂浮选预处理系统存在的问题,采取增设管道泵、改造乳化器出料管、将浮选加药点改为泵前加药等措施,优化了药剂乳化效果,提高了浮选数量效率,为选煤厂节约了生产成本。     

射流器式浮选药剂添加系统优化实践

针对水峪选煤厂浮选系统存在的浮选尾矿灰分偏低等问题,制定了系统优化方案:建立射流器式药剂添加系统,优化选取射流器加药方式、射流器孔径和管路过滤器形状;改造完成后浮选尾矿灰分达70.86%以上,尾矿煤泥灰分达65.66%以上,不但达到了集团公司规定的考核指标,而且每年可增加经济效益2 967.60万元。     

汪家寨选煤厂以技术改造提升产效的实践

汪家寨选煤厂因入洗原煤质量差、旋流器易堵塞、介耗高、煤泥水浓度高、浮选效果差等问题,阻碍了矿井正常生产;通过对劣质原煤分级入选,原煤选前二次筛分,改进浮选加药技术,更新浮选精煤脱水设备,降低介耗等技术改造措施,控制了重介质旋流器入料粒度上限,提高了选煤厂的分选效果和经济效益。     

Metabolism of trideuterated iso-lignoceric acid in rats in Vivo and in human fibroblasts in culture

Saturated very long chain fatty acids (fatty acids with greater than 22 carbon atoms; VLCFA) accumulate in peroxisomal disorders, but there is little information on their turnover in patients. To determine the suitability of using stable isotope-labeled VLCFA in patients with these disorders, the metabolism of 22-methyl[23,23,23-²H₃]tricosanoic (iso-lignoceric) acid was studied in rats in vivo and in human skin fibroblasts in culture. The deuterated iso-VLCFA was degraded to the corresponding 16- and 18-carbon iso-fatty acids by rats in vivo and by normal human skin fibroblasts in culture, but there was little or no degradation in peroxisome-deficient (Zellweger’s syndrome) fibroblasts, indicating that its oxidation was peroxisomal. Neither the 14-, 20-, and 22-carbon iso-fatty acids nor the corresponding odd-chain metabolites could be detected. In the rat, the organ containing most of the iso-lignoceric acid, and its breakdown products, was the liver, whereas negligible amounts were detected in the brain, suggesting that little of the fatty acid crossed the blood-brain barrier. Our data indicate that VLCFA labeled with deuterium at the ω-position of the carbon chain are suitable derivatives for the in vivo investigation of patients with defects in peroxisomal β-oxidation because they are metabolized by the same pathways as the corresponding n-VLCFA. Moreover, as iso-VLCFA and their β-oxidation products are readily separated from the corresponding n-fatty acids by normal chromatographic procedures, the turnover of VLCFA can be more precisely measured. A preliminary report of part of this work (Reference 18) was presented at the 5th International Symposium on the Synthesis and Applications of Isotopes and Isotopically Labelled Compounds, Strasbourg, France, June 20–24, 1994.     

佛山市顺德新城区降水中污染物的监测和分析

为掌握佛山市顺德新城区降水中污染物的情况,2015年7月至8月,文章作者分别在雨天进行了降水取样,对降水中的pH、电导率、常见阴离子(F-、Cl~-、NO_3~(2-)、SO_4~(2-))及部分重金属(铅和镉)进行监测分析。选择有相关数据的珠江三角洲和石家庄、厦门等地的降水中污染物的情况进行对比。结果表明,顺德新城区降水中的p H和部分阴离子浓度优于珠江三角洲平均值,酸雨类型属于硫酸和硝酸混合型;其水体洁净程度略差于石家庄;铅和镉的浓度也高于厦门,甚至部分超出了人体能直接接触的安全范围。     

高效液相色谱法分析化妆品中微量成分的研究进展

综述了高效液相色谱法在化妆品中防腐剂、防晒剂中紫外线吸收剂以及性激素的检测等几个方面的应用;同时,介绍了分析所用的色谱柱、流动相、使用的检测手段以及样品的提取方法;最后针对目前存在的问题,提出了高效液相色谱用于化妆品中微量成分分析的研究方向和发展前景。     

我国硝酸工业生产技术新进展

系统叙述了我国硝酸工业2000-2007年生产现状及主要技术成果,尤其指出了国产"四合一"机组的成功投运,使我国硝酸国产化装置取得较大的进步,表现在吨酸的铂耗、氨耗和能耗等方面接近国外引进装置水平,同时介绍了国外双加压法硝酸生产技术的进展.我国已成为硝酸生产大国,仍需以先进的技术改造和发展我国硝酸工业,确保我国硝酸工业健康有序地发展,加快从硝酸生产大国向强国迈进的步伐.     

Denitrification in shallow groundwater in a coastal agricultural area in Japan

In a coastal agricultural area in the central part of Japan (Shizuoka), we found decreasing nitrate concentration with depth in a shallow groundwater, where the depth to water table varied between 0.6 and 1.2 m below ground surface. High nitrate concentrations (5–29 mg N L^–1) were often observed in the upper layer (0–2 m) of the groundwater, but the concentration decreased to less than 1 mg N L^–1 in the deeper layer. Ammonium was scarcely detected, and the concentration of dissolved oxygen was usually low (< 1 mgO₂ L^–1) in the groundwater. Nitrate in the groundwater often had very heavy nitrogen stable isotope ratios (>20{}). There was a negative relationship between nitrogen stable isotope ratio of nitrate and its concentration. When nitrate was injected into the groundwater with acetylene and bromide (a conservative tracer), nitrate concentration decreased to 20% of the initial level within 5 days, accompanied by the increase in nitrite and nitrous oxide concentration and a little change in bromide concentration. These results indicate that microbial denitrification plays a potential role in the decrease of nitrate in shallow groundwater at the study site.