共查询到20条相似文献,搜索用时 9 毫秒
1.
为合理有效地利用长焰煤中的细粒煤泥,对其进行浮选试验研究,考察了分散剂和聚丙烯酰胺PAM对其浮选的促进作用。结果表明,作为动力用煤,长焰煤精煤灰分不能太低,宜为16~20%,煤油和仲辛醇用量分别应在1000 ~ 2000 g·t-1和150 ~ 250 g·t-1之间,以保证产品质量并控制药耗。分散剂可消除煤颗粒表面的高灰细泥罩盖从而促进长焰煤的浮选。不同分散剂对精煤可燃体回收率的促进作用从大到小依次为:多聚磷酸钠>六偏磷酸钠>焦磷酸钠,与它们的分子构型以及其中阴离子的量有关。其中多聚磷酸钠在3000g·t-1时对应精、尾煤灰分分别为19.64%和69.33%,精煤可燃体回收率提高11.80%。使用少量聚丙烯酰胺可以使精煤灰分降低,可燃体回收率提高,使用少量阴离子聚丙烯酰胺可得到灰分17.25%、可燃体回收率94.23%的精煤,对应尾煤灰分66.27%。 相似文献
2.
通过浮选试验、Zeta 电位测试、吸附量试验和扩展的DLVO理论计算,考察六偏磷酸钠对浮选中煤泥与黏土颗粒间相互作用的影响,研究六偏磷酸钠的作用机理。结果表明:高岭石含量较多时会对煤泥浮选产生不利影响,高岭石含量达到20%,精煤回收率降低18.70%;低用量的六偏磷酸钠会抑制高岭石上浮而对煤影响较小,高用量的六偏磷酸钠会失去选择抑制性;六偏磷酸钠用量为1000g/t时,能使煤和高岭石的Zeta电位分别从-25mV、-39mV移至-32mV、-57mV,增强了颗粒间静电排斥作用;同时,六偏磷酸钠水解形成的大分子吸附于高岭石表面,当颗粒相互靠近时产生较强的排斥力,增强了颗粒之间的空间稳定化作用能。 相似文献
3.
This research addresses two important issues confronting coal flotation plants in Australia, the use of saline water and the processing of clayey coal. Two coal samples obtained from BHP Billiton Mitsubishi Alliance (BMA) and Xstrata were tested to represent coarse coal flotation and fine coal flotation, respectively. Saline water with low, medium and high ionic strengths and individual electrolytes encountered in the flotation plants were used. It was found that saline water had a more pronounced effect on fine coal flotation than coarse coal flotation despite similar mineral compositions and clay mineral types present. Although saline water increased froth stability in both fine and coarse coal flotation, coal particle aggregation only occurred between fine coal particles resulting in an increased recovery of coal particles as well as the entrapment of fine gangue minerals. 相似文献
4.
针对通化地区黏土含量大、主导粒级为高灰细粒级的难浮煤泥,采用小锥角水力旋流器进行高效脱泥探索,旋流器产物进行粒度和矿物组成分析,底流进行分步释放浮选试验。结果表明,采用Φ150 mm小锥角水力旋流器作为煤泥浮选前脱泥的主要设备;Φ150 mm与Φ75 mm旋流器串联脱泥工艺中,0.045 mm粒级脱除率达到67.73%,灰分为50.10%,且高岭石、伊利石等黏土矿物在Φ75 mm旋流器溢流中实现富集;Φ150 mm与Φ75 mm旋流器底流单独或混合入料浮选,精煤产率(占本级)及可燃体回收率均比原煤泥直接浮选提高了2~3倍。 相似文献
5.
以天然油脂棉籽油和工业副产品为主要原料,合成出脂肪酸单甘油酯硫酸盐PGS,将之作为浮选促进剂(3%),与柴油(27%)、水(70%)制备出新型煤用乳化浮选捕收剂ZFC。分别以ZFC和柴油作为捕收剂,对两种1/3焦煤进行浮选速度试验,并应用一级浮选动力学方程进行拟合,得到两种煤样的动力学方程,通过对比得出:以ZFC做捕收剂,所用煤样的浮选速率常数和浮选速度均优于柴油。对PGS促进剂作用前后煤样的疏水性、红外光谱、润湿热进行检测,结果表明:PGS促进剂和煤粒表面发生化学吸附,促进剂的疏水性基团朝外,因此提高了煤粒表面的疏水性;乳化药剂和煤粒的吸附强度及稳定性显著提高,煤粒在随气泡上升过程中不易脱落,从而提高了浮选速度。 相似文献
6.
7.
以煤泥水中常见的三种黏土矿物为对象,通过浮选、沉降、过滤实验研究了不同黏土对煤泥水处理的影响,结果表明:蒙脱石的存在降低了煤泥的可燃体回收率和浮选速率,引起沉降恶化和过滤时间的增长。伊利石的存在主要影响浮选速率,在保证浮选时间的前提下,对可燃体回收率没有影响。高岭石的存在对煤泥水处理影响较小。 相似文献
8.
9.
10.
In this study, the effect of bentonite and kaolinite minerals with low and high crystallinity on pulp rheology and the flotation of copper and gold minerals was investigated. It was found that clay minerals modified the pulp rheology depending on the type of clay minerals present. Bentonite, a 2:1 structured clay mineral increased pulp viscosity more significantly than kaolinite, a 1:1 structured clay mineral, and poorly crystallized kaolinite increased pulp viscosity more than well crystallized kaolinite. It was also found that pulp rheology modified by clay minerals was strongly correlated with copper and gold flotation. The higher pulp viscosity corresponded to the lower copper recovery. While high pulp viscosity was related to the decreased gold flotation, slightly increased pulp viscosity by clay minerals enhanced gold flotation. 相似文献
11.
In this study, three lignosulfonate-based biopolymers, DP1775, DP1777 and DP1778 with different compositions were examined as dispersants in copper flotation in the presence of kaolinite. While rheological measurements indicated that these biopolymers dispersed the kaolinite aggregates, flotation results revealed that the three biopolymers increased the copper recovery, with a decline in copper grade, which was attributed to an interaction of biopolymers with the frother modifying the froth and enhancing the mechanical entrainment. Two-phase foam characterisation revealed a larger height in the blends of biopolymer and frother, which in turn promoted the mechanical entrainment in flotation. The dispersing and foaming abilities of biopolymers were governed by their structural features such as the content of functional groups, the molecular weight and counterions. This study indicates that when selecting a polymeric dispersant in flotation to deal with clay minerals, its froth property should also be taken into consideration. 相似文献
12.
13.
14.
煤炭作为化工原材料的应用途径正逐步向精细化、高端化利用转变,将高炭煤深度脱除矿物质制备成超纯煤可以作为高附加值先进炭素材料的原料。以太西无烟煤为原料,采用自制的微泡浮选柱通过Box-Behnken试验设计方法优化浮选试验,借助XRF,XRD和SEM-EDS分析了最佳浮选条件下的浮选精煤,进一步明晰微泡浮选方法深度脱除矿物质的过程和不同矿物质对无烟煤深度脱矿的影响。同时也采用了NaOH-HCl方法深度脱除无烟煤中的矿物质,通过XRD,SEM-EDS分析脱矿样品的性质,明确无烟煤中矿物质的脱除机理以及限制深度脱矿的因素。微泡浮选试验表明,当捕收剂用量3.36 kg/t、起泡剂用量1.81 kg/t和调浆强度4 560 r/min时,浮选效果最佳,能得到灰分0.52%、产率66.25%的浮选精煤,由测试表征可知细泥罩盖和粒度小于2μm、有机质占95%以上的连生体颗粒是限制微泡浮选方法深度脱矿主要原因。NaOH-HCl脱灰试验表明,随着样品粒度减小,样品灰分显著降低,当样品的体积平均粒径为8.01μm时,脱矿效果最佳,能得到脱矿率86.81%、灰分0.36%的脱矿样品。而无烟煤中低反应活性的石英和伊利石以及被煤基质包裹的微细硅酸盐矿物影响太西无烟煤的化学深度脱灰。基于微泡浮选方法和NaOH-HCl方法在高炭煤深度脱矿过程中存在的极限问题,提出浮选-化学联合深度脱灰方法对太西无烟煤进一步深度脱灰,首先通过浮选预处理减少石英和伊利石等低反应活性的矿物质总量,再将浮选精煤中存在的矿物质与NaOH反应生成水溶性的硅酸钠和易溶于酸的硅铝酸钠而被脱除,并以此构建了浮选-化学联合方法深度脱灰历程描述模型,最终得到超低灰(0.12%)、高碳、高发热量能制备成高附加值炭材料的超纯煤样品。 相似文献
15.
16.
17.
18.
针对内蒙古乌海矿区高灰难选煤浮选精煤灰分高的问题,在煤泥分步释放浮选试验的基础上,分析调浆时间、泡沫层厚度对浮选精煤灰分的影响,并对磨矿-浮选工艺的降灰效果进行研究。试验结果表明:高灰细泥与中间密度级连生体的非选择性上浮是造成浮选精煤灰分高的重要原因,高紊流流态对矿粒的擦洗效应并未改善浮选选择性,而厚泡沫层可有效抑制高灰细粒级对精煤的污染。磨矿-浮选可使煤泥得到更好的分选,在磨矿时间为0.5 min、入浮矿浆浓度为80 g/L、搅拌强度为1 800 r/min、柴油用量为600 g/t、仲辛醇用量为100 g/t、充气量为0.25 m3/(m2·min)的条件下,通过浮选可获得灰分为14.98%、产率为61.02%的精煤。 相似文献