利用表面活性剂改善粘胶过滤性能

通过对影响粘胶过滤性能原因的分析及表面活性剂对粘胶生产过程多方面的改善，导出表面活性剂改善粘胶过滤性能的原因和结果。     

选煤生产中表面活性剂的应用

选煤生产几乎全部是湿法工艺,特别是煤泥水的处理和细粒煤的分选、脱水,大有表面活性剂的用武之地,本文根据表面活性剂的性质和选煤生产各环节的作用作一介绍,使表面活性剂在选煤工业中进一步得到广泛应用.     

用表面活性剂强化碳酸氢钠悬浮液的过滤

用表面活性剂强化碳酸氢钠悬浮液的过滤纯碱生产中，粗碳酸氢钠从母液中分离出来，是一个重要的工序。转筒式真空过滤机是分离碳酸氢钠的主要设备，这种过滤机在碳化良好运行时可保证得到产率为５１～５２％的碳酸氢钠，这种碳酸氢钠含水２０～１７％。表面活性剂在相间界...     

表面活性剂在浮精过滤时的协同效应

絮凝剂作为助滤剂在 80年代已在我国选煤厂应用 ,不但降低精煤水分 2 %～ 4% ,而且可提高过滤机的处理能力一倍以上。絮凝剂并不是对每种浮选精煤都有效 ,这固然与煤炭性质有关 ,但是否与作为浮选药剂的表面活性剂有关 ,尚不可知。表面活性剂对浮精过滤的影响基本上已有定论。为了摸清在絮凝助滤时表面活性剂对浮精过滤的影响 ,笔者对其进行了系统研究 ,发现表面活性剂与絮凝剂在浮精过滤时 ,相互之间有协同作用。论述了起泡剂对浮选精煤过滤影响的原因 ,以及采用絮凝剂助滤的必要性。探讨了表面活性剂的种类在絮凝剂助滤时的协同作用     

表面活性剂对煤泥离心过滤脱水的助滤研究

研究了不同离心因数下,十二烷基苯磺酸钠、咪唑啉两种表面活性剂对煤泥离心过滤脱水的助滤作用;两种活性剂均可以显著降低煤泥离心过滤的滤饼水分,但前者的助滤效果更佳;详细分析了表面活性剂的助滤机理。     

表面活性剂在抛光液中应用

讨论一种用于金属类的抛光液的制备和性能。它由磨料与表面活性剂(非离子型与阴离子型)、助剂与水组成的溶液,该溶液用Na2CO3将pH值调至8～9,本抛光剂特别适于抛光钢制品与不锈钢制品,而且可以减少原材料消耗,缩短加工时间。     

表面活性剂在煤炭浮选中的应用研究

将多种表面活性剂用于煤炭浮选,筛选较好的表面活性剂或其组合作为煤炭浮选促进剂,并对浮选药剂制度进行调整以提高浮选工艺指标。试验得到较好的煤炭浮选促进剂为OSE[m(辛基酚聚氧乙烯醚OP-4)∶m(失水山梨醇单油酸酯Span 80)∶m(聚氧乙烯蓖麻油EL-40)=4∶4∶2.5]。较好的浮选药剂制度为:抑制剂羧甲基纤维素钠(CMC)20 g·t-1,OSE 2.7 g·t-1,捕收剂TH102(主要成分为柴油和橄榄油)900 g·t-1,起泡剂GF油66 g·t-1。按照上述药剂制度进行浮选试验,精煤产率为79.51%,精煤灰分为11.34%,可燃体回收率为88.16%,对比不加促进剂与抑制剂浮选,精煤产率提高4.05百分点,可燃体回收率提高4.63百分点,精煤灰分降低0.24百分点。另外,试验中加入表面活性剂OSE与抑制剂CMC可提高浮精的过滤速率,降低精煤滤饼含水率。     

表面活性剂在液体洗涤剂中的应用

论述了表面活性剂在液体洗涤剂中的应用现状和发展趋势,分析了几种典型的阴离子表面活性剂、非离子表面活性剂和两性表面活性剂的特性和应用,并指出随着液体洗涤剂的发展趋势表面活性剂也朝着绿色和安全的趋势发展。     

表面活性剂的应用与发展

介绍了几种表面活性剂的应用特征与总体发展趋势.     

The Effect of Flocculants and Surfactants on the Filtration Dewatering of Iron Ore Fines

Abstract

The filtration and separation characteristics of iron ore fines have been investigated. The experimental work included: characterization, evaluation of suitable flocculants to enhance settling and dewatering rate, determination of optimum dosages of flocculants, and influence of surfactants on nitration dewatering of both flocculated and unflocculated iron ore fines by vacuum filtration. The results showed that 1) the settling rate can be enhanced many-fold (from 2.52 to 90 m/h) by a suitable flocculant, 2) the residual filter cake moisture content can be reduced from 18.2% without reagents to 12.6% with suitable surfactant dewatering aids while the filtration rate can be enhanced from 4.8 to 97.2 L/h with suitable dewatering filter aids, and 3) the specific cake resistance to filtration can be brought down from 8.6 × 10⁹ to 1.0 × 10⁹ m/kg by using a surfactant sodium petroleum sulfonate at a concentration of 1.47 × 10^?3 kg/t. The economics of using flocculant filter aids and surfactant dewatering aids before thermal drying is described and discussed.     

Effects of pore size, suspension concentration, and pre-sedimentation on the measurement of filter medium resistance in cake filtration

Theoretical and experimental study was conducted on the factors influencing the measurement of filter medium resistance by Ruth’s equation. It was determined that a filter medium having small pore size does not always give high filter medium resistance. The appropriate pore size of filter medium for filtration was analysed. The resistances of filter media measured with thick suspensions by Ruth’s equation have negative values. This phenomenon can be analyzed as the effect of sedimentation during the long filtration time due to thick suspension. When sedimentation occurs before the start of filtration, the filter medium resistance measured by Ruth’s equation gives a large value. It was determined that the result of the filtration of sediment was included in the filter medium resistance. A new method for measuring filter medium resistance by the filtration of the sediment is proposed. This method excludes the effects of suspension concentration and pre-sedimentation.     

滤饼过滤过程的计算机模拟研究

利用自行设计的计算机模拟程序 ,对物料粒度、浆体浓度、过滤压差对过滤脱水的影响以及滤饼分层现象进行了计算机模拟 ,并通过实验进行了验证。结果表明 ,模拟结果虽然在数值上与实验结果有一定差距 ,但定性方面能够很好地与实验结果相吻合。     

过滤理论研究与过滤实践中的几个问题

对过滤理论研究的进展情况进行了较系统的介绍与分析 ,并就工业生产中存在的问题提出了看法。     

Filtration properties of two Tunisian clays suspensions: effect of the nature of clay

The knowledge of the filtration properties are very important and can ascertain if a clay is suitable or not for use as a lining material for waste disposal. The general objective of our work is to determine a relation between structure and microtexture of two Tunisian clays (C1 and C2) and macroscopic properties of cakes formed by filtration. The result of permeability by water and waste solution (pH = 3) shows that the clay C2 is more impermeable than C1. In addition, the cake obtained after filtration test by filter-press for both clays present many interesting observations. However, for a ratio of (40%) of clay–water, the thickness of cake (e) in the case of C2 is more important (e = 10mm) than for C1 (e = 7mm). Similarly, the water retention (WR) is of order 34% for C2 and 26% for C1. This is due to the mineralogical composition of sample C2 which is essentially the smectite (swelling clay). Although, (WR) and (e) are slightly changed using the waste solution, it exist a lowering of plasticity of clay filter cake. This is illustrated by the SEM images that showed an interconnected micro-crack for the cake of sample C2, due to the degradation by acidic attack.     

The Vacuum Filtration of Iron Ore Ultrafines

ABSTRACT

The dewatering of fine particles (? 0.5 + 0 mm) derived from iron ore processing is a topic of increasing importance to Australian producers. With little previous published work in this area, it is difficult to predict how these materials are going to dewater, in particular during vacuum filtration. The work described in this paper was therefore undertaken in order to help overcome this paucity of background information. The sample of iron ore that was tested responded well to vacuum filtration provided that anionic flocculants were used as a filter aid. In the presence of these polymers, cake formation times were very short (mainly below 10 seconds) and the moisture levels of 18 mm thick filter cakes were reduced to 10–11 wt% after dewatering times of only 40 seconds. By comparison, the cationic and nonionic flocculants tested were much less effective. The mathematical model devised by Wakeman shows considerable promise as a toolfor predicting the kinetics of desaturation.     

An experimental and theoretical study on the initial period of cake filtration

Experimental measurements were made of the average specific cake resistance during the initial period of cake filtration, and the theoretical calculations about the period were also performed. The “filtration-permeation method” in the filtration cell of small area was used to measure the flow rate during the initial period of filtration, which is essentially characterized by the large flux due to fast flow rate and the rapid change of flow rate within a relatively short time interval. The measured average specific cake resistances of thin cakes which represent the cakes of initial period had very large values compared to the overall average specific cake resistance. This experimental result was contrary to the conventional theory about the initial period. Applying the “unified theory on solid-liquid separation” to the initial period, the average specific cake resistances at the initial period can have the large values--more than two times greater than that of the overall value.     

Experimental investigation into compression properties of integrated coal gasification combined cycle fly ashes on a ceramic filter

The compression properties of IGCC (integrated coal gasification combined cycle) fly ash cake on a ceramic filter were carefully investigated under well-controlled conditions. Overall cake porosity and pressure drop of dust cake of three different particles of geometric mean diameters of 3.7, 6.2, and 12.1 Μm, and dynamic shape factors of 1.37, 1.57 and 1.65, respectively, were investigated, at face velocities of 0.02-0.06 m/s. Overall cake porosity was strongly dependent on face velocity, mass load, and particle size. The expressions for overall cake porosity, considering the compression effect, and pressure drop across the dust cake were developed with good agreement with experimental results.     

A unified theory on solid-liquid separation: Filtration, expression, sedimentation, filtration by centrifugal force, and cross flow filtration

Based upon a new conception that the solid compressive pressure on a cake surface is not null, almost of all solid-liquid separation operations have been re-examined. For cake filtration, the phenomenon caused by the solid compressive pressure on a cake surface is discussed for thin cake. New expression and hindered sed-imentation theories are developed by above new conception using Darcy’s equation. Application of the new conception to centrifugal filtration and tangential filtration is also discussed. Above results lead to the conclusion that cake filtration, expression, hindered sedimentation, centrifugal filtration and tangential filtration can be described with a unified theory, and the main difference between the operations is only the boundary condition of cake.