橡胶促进剂M过滤分离工艺实验研究

由于橡胶促进剂M在酸化后含有大量的水分,前期研究表明通过添加表面活性剂预处理可以有效降低固液分离后滤饼的含水量。为了研究经表面活性剂处理后悬浮液的过滤方法与效果,分别采用加压过滤、真空抽滤、离心过滤的分离方法进行了过滤分离实验,并对不同分离方法下滤饼质量进行检测。研究结果表明,采用真空抽滤方法对添加表面活性剂预处理后的橡胶促进剂M悬浮液进行过滤分离,并通过水洗滤饼,可以大幅度降低滤饼的含水量,并能满足橡胶促进剂M的质量要求。     

气流干燥法在橡胶硫化促进剂生产工艺中的应用研究

结合橡胶硫化促进剂的物性特点设计应用于橡胶硫化促进剂(简称促进剂)的生产工艺的气流干燥系统,通过选择直管气流干燥设备处理经离心机脱水后的促进剂滤饼可以起到加大干燥强度;缩短干燥时间;提高热效率的作用,从而优化了气流干燥法的工艺参数。     

用表面活性剂强化碳酸氢钠悬浮波的过滤

摘１５００用表面活性剂强化碳酸氢钠悬浮波的过滤－Ｂａｒｂｉｎ，Ｍ．Ｂ．《ｎｐ．ｘＭ．）。１９９３年，Ｖｏ１．６６．Ｎｏ７Ｐ１６４４－６．（俄）ＴＱ１１４．１７３在碳酸氢钠悬浮液或洗水中加入表面活性剂对碳酸氢钠滤饼含水量及其产率的影响进行了研究。滤饼水...     

活性硅酸钙过滤分离工艺实验研究

由于活性硅酸钙在加压过滤后得到的滤饼含水率高达66％左右,加重了后续干燥工段的负荷,耗能较高,影响了生产效率.本文在测定活性硅酸钙基本物性的基础上,确定活性硅酸钙是一种高孔隙率、蜂窝状结构、粒径较小的轻质材料;通过实验确定了加压工艺条件;采用添加表面活性剂的预处理技术,研究了添加阳离子表面活性剂FL02的适宜添加量以及滤液循环使用的方法.研究结果表明,在加压过滤之前,向质量分数为10％的活性硅酸钙悬浮液中加入表面活性剂FL02(初次添加量占悬浮液质量的0.5％,后续的4～5次添加量占悬浮液质量的0.15％),混合均匀后,在0.35 MPa的操作压力下,得到的滤饼含水率了降低至54％左右.研究结果为工业应用提供了参考依据.     

专利文摘

一种碳化硅橡胶耐磨材料及其制备方法本发明提供了一种碳化硅橡胶耐磨材料制备方法。该耐磨材料组成为:天然橡胶或/和合成橡胶、防老剂、促进剂和活性剂、硫化剂、填料、偶联剂和甲苯;加工工艺为:碳化硅表面化学处理,橡胶塑炼、混炼、硫化。其中防老剂为2,2,4-三甲基-二氢化喹啉聚合体,促进剂和活性剂为2-硫醇基苯并噻唑、氧化锌和硬脂酸混合     

橡胶促进剂M项目介绍

橡胶促进剂M为通用型橡胶硫化促进剂,可单独使用,亦可混用。它是生产噻唑类硫化促进剂不可缺少的中间体,经深加工后能够制造出DM、CZ、NOBS、NS、DZ等各种橡胶促进剂。它也可用作硫化矿物捕集剂、农药(氢硫剂或M剂)和腐蚀抑制剂,纯品还用作金属特种试剂。 市场情况 我国现有橡胶促进剂60类、16个品种,目前总生产能力约2.4万t/a,其中橡胶促进剂M约占30％左右。随着我国橡胶工业的发展,对橡胶促进剂的需求量会不断增加。     

一种溶剂法精制橡胶硫化促进剂M的方法

正鹤壁市恒力橡塑股份有限公司开发出一种溶剂法精制橡胶硫化促进剂M新方法。在高压生成物与乙二醇为1:3~7比例下,使粗M全溶,冷却,滴水,静置分层,将上清液采用冰水浴降温冷却析出M,加入CS_2,室温萃取1 h,过滤,滤饼加水打浆后加热去除物料夹带的CS_2,抽滤,洗涤,干燥得M;滤液静置分层,上     

改性高岭土—用于氟橡胶CKΦ-26胶料的活性填充剂

季胺盐在噻唑类促进剂存在下对于不饱和极性橡胶用硫黄硫化时可起活化作用,对氟橡胶双酚硫化起催化作用。研究含有用表面活性剂改性的天然高岭土的ckφ-26混炼胶用双酚类硫化有着实际意义。高岭土用表面活性剂水溶液改性时,表面活性剂均匀分布于填     

硅钙渣过滤脱水影响因素的实验研究

对高铝粉煤灰生产氧化铝联产硅钙渣进行物性分析的基础上,研究了过滤压力及颗粒粒径对滤饼含水率的影响.分析了季铵盐类表面活性剂FL02对硅钙渣滤饼含水率的影响并用红外光谱进行表征,分析作用机理.结果表明,硅钙渣为中等可压缩性物料;过滤压力取0.3 MPa时,硅钙渣滤饼含水率由49.73％降到44.56％;颗粒粒径为0.075～0.125 mm时,硅钙渣滤饼含水率最低为41％;加入季铵盐类表面活性剂FL02使滤饼含水率降低,最适宜添加量为0.75％(相对干固相的质量分数),硅钙渣滤饼含水率从44.71％降到39％,由红外光谱看出季铵盐类表面活性剂FL02的亲水基与硅钙渣表面羟基键合形成氢键,致使表面自由羟基数量减少.     

橡胶硫化促进剂M在我省试制成功

为了适应橡胶工业的发展,平乡县化工厂试制的新产品橡胶硫化促进剂 M,最近通过了技术鉴定。鉴定结果表明,该厂试制出的硫化促进剂 M,其各项质量指标均达到了部颁标准。橡胶硫化促进剂 M 学名2—巯基苯并噻唑。它是通用型橡胶硫化过程中一种不可缺少的化学药剂。它具有能够缩短硫化时间,降低硫化温度,减少硫化剂用量,提高橡胶     

Residual saturation and dewatering of fine coals and filter cakes

Cake dewatering aims to minimise filter cake moisture contents. This may be aided by flocculating agents or surfactants, but the former can actually increase moisture contents and both types of chemical additive are expensive. Steam dewatering offers a technical alternative to liquid displacement by air. This latter is far away the most common technique adopted for filter cake dewatering, and has been studied to the extent that the process performance can be predicted and assessed through capillary pressure curves and generalized design charts. Other more esoteric techniques such as ultrasonic dewatering of cakes may offer further technical alternatives in the future.     

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.     

煤气化细渣陶瓷膜真空脱水试验与数值模拟

气化细渣是煤炭气化过程的废弃物,高效脱水是其资源化利用、减量化处置的必要前提。本文采用陶瓷膜真空过滤系统开展了脱水实验并对脱水过程进行了数值模拟。气化细渣料浆浓度和液下吸附时间影响滤饼厚度且滤饼厚度增加导致水分运移路径增长,使得有效脱水时间增加;滤饼脱水过程的脱水速率值呈现非线性降低趋势且滤饼水分极限值为40%,这与气化细渣物化性质有关;真空度>0.08MPa时气化细渣滤饼中“通道水”能够在约24s有效脱除。Fluent数值模拟过程选用了欧拉模型并确定了陶瓷膜滤板和气化细渣滤饼的阻力系数,脱水过程的实验值与模拟结果误差小于5%,证实了模型可靠性。模拟过程分析了气化细渣脱水过程中压力场和水分含量分布云图的演变规律,结果表明,增加脱水系统真空度、降低滤饼厚度、提高“通道水”比例以及增大气化细渣颗粒等效当量直径能够提高气化细渣脱水效率。此外,陶瓷膜真空脱水过程所得滤液洁净度高且部分指标达到了工业用水的标准。     

Thermal Dewatering (TDW) to Reduce the Water Content of Sludge

Thermal dewatering describes the process whereby a heating plate and heat supply unit are incorporated into a filter press system to improve separation of water from sludge. The performance of our thermal dewatering system for both wastewater and waterworks sludge was measured and compared with mechanical dewatering in terms of water content, dewatering velocity, cake specific resistance, and energy consumption. Dewatering velocity was improved by a factor of two, cake water content was lower, and specific cake resistance was improved. However, energy consumption was higher. Thermal dewatering systems may be economical and have practical application to improving dewaterability.     

Influence of surfactants on flocculation and dewatering of kaolin suspensions by cationic polyacrylamide (PAM-C) flocculant

This paper reports the result of studies on flocculation and dewatering of kaolin suspensions by cationic polyacrylamide (PAM-C) flocculants in presence of surfactants. The surfactants used were namely anionic sodium dodecyl sulphate (SDS), cationic cetyl trimethyl ammonium bromide (CTAB) and non-ionic TritonX 100, which is a polyoxyethylenic ether compound. The unflocculated kaolin has a very slow settling rate of about 0.03 cm/s and can be improved by more than ten times using PAM-C as a flocculating agent. PAM-C adsorbs on kaolin primarily through electrostatic attraction and the flocculation is governed mainly by charge neutralisation and bridging. Partial pre-coating of kaolin with all three surfactants leads to both physical adsorption as well as chemisorption at PAM-C. Pretreating the kaolin with surfactants can further increase or decrease settling rate depending on the type of surfactant used. However, the flocs thus formed shows better filtration and dewatering behaviour estimated in terms of reduction in specific resistance to filtration (SRF) and cake moisture. The minimum SRF occurs under conditions corresponding to far lower adsorption of PAM-C than that for best flocculation. Simultaneous addition of PAM-C and each of the three surfactants decreases settling rate and sediment volume markedly and does not reduce SRF any further but they all reduce cake moisture substantially. The reduction in cake moisture for different PAM-C: surfactant mixture is in the following order: PAM-C: SDS (1:1)>PAM-C: TX 100(1:1)>PAM-C: CTAB(1:1). Low cake moisture in comparison with PAM-C alone, may be a result of reduction in entrapment of excess water in the smaller flocs formed by simultaneous addition with surfactants and to some extent due to hydrophobicity caused by adsorption of surfactants.     

Application of Enhanced Vacuum Filtration to Dewatering of Fine Coal Refuse

Abstract

It is difficult to reduce the moisture content of fine coal refuse to a satisfactory level because of the high mineral content and the large capillary forces associated with small particle sizes. An experimental investigation of important operating variables on dewatering of fine coal refuse is reported. The cake permeability, cake formation time and final moisture content are used to measure the efficiency of moisture removal. Factors that were studied are the addition of coarse particles, level of vacuum, pH and the use of coagulants, flocculants and surfactants as additives. Addition of a flocculant was the most effective single means of improving dewatering and the permeability could be increased by more than an order of magnitude and the moisture content lowered by as much as 0.05 kg water/kg dry cake. It was found that the ionic nature and molecular weight of the flocculant, the flocculant dosage, the mixing time and the mixing intensity must be carefully studied to obtain optimal performance.     

Effect of Hydrodynamics During Crystallization on Mechanical Dewatering of Salicylic Acid

Mechanical cake dewatering is always desired to reduce the load on thermal dewatering (drying). Any change in the upstream process such as crystallization can have a significant influence on the filtration as well as cake dewatering characteristics. The present study deals with the effect of hydrodynamics (mixing intensity) during salicylic acid crystallization on the air dewatering characteristics in the subsequent pressure filtration. The mixing conditions during crystallization were varied by using three different types of agitators (anchor impeller [AI], curved blade turbine [CBT], and bar turbine [BT]) and by varying the speed of agitation. The effect of operating pressure and dewatering time on the final moisture content of the cake was also studied.

The crystal properties (crystal size and size distribution) were found to vary with the mixing intensity, which further influenced the cake dewatering kinetics as well as the residual moisture content. An AI, which is a laminar flow impeller, produced crystals with a wide size distribution and higher mean particle size, which resulted in cake with high porosity and hence higher moisture content. The high porosity (as well as high cake permeability) caused early air breakthrough, which resulted in ineffective dewatering of cake. Therefore, in this case the residual moisture in cake was found to be higher (27%) even at higher dewatering pressure (1.5 bar gauge) and longer dewatering time (90 s). A BT creates high turbulence during mixing and produced crystals with a relatively narrow size distribution and lower mean particle size, which provided low-porosity cakes. Such cakes could be efficiently dewatered and the final cake moisture content was found to decrease to about 15%, a significant improvement in the filterability of the cake. The dewatering data were modeled according to the correlation between irreducible cake saturation and capillary number for predicting the cake dewatering characteristics (residual moisture as well as dewatering kinetics) and the results were compared with the experimental data.     

高含水率中药渣的带式压滤机压滤脱水试验

分析中药渣中的水分,阐述中药渣受挤压作用时的脱水机理,结合中药渣的特性和带式压滤机的脱水工艺,对压滤机的布料器进行改造,增加两级分料螺旋,改善压滤效果,使其适用于中药渣脱水试验,增加物料处理量,减少溢料现象,降低污水含固率,减少运行人员劳动强度。采用控制变量法,试验研究压滤机的不同脱水段、压力、带速、中药渣初始含水率等4个因素对脱水效果的影响,结果表明：物料初始含水率越大,不同脱水段的脱水率越大,滤饼的含水率越大;Ⅰ级脱水辊对物料脱水效果影响最大,楔形预压段对物料脱水效果影响最小;中药渣的初始含水率不宜超过80.16%;Ⅰ级脱水辊压力选择0.2～0.6MPa较合适;带速在0.3～0.5m/s范围内时,滤饼的含水率在65%～ 66%之间,脱水效果较好。     

阴极滤布对活性污泥电渗透脱水的影响(英文)

The mechanical dewatering of activated sludge is troublesome due to its high compressibility of solids. The dewatering can be enhanced dramatically by the use of electroosmosis,in which an electric field is applied to the sludge cake.In this study,the influence of filter cloth on the cathode on the dewatering of activated sludge was investigated.It was found that thicker filter cloth led to lower water removal from the sludge cake,so a stainless steel cathode net with small pore size instead of filter cloth was applied,which improves the dewatering efficiency and reduces the electric power consumption.Moreover,water absorbent materials were helpful to remove the water from the sludge cake.For the electroosmotic dewatering at 7 kPa and 24 V·cm-1,the water content in the sludge cake decreased to 60%(by mass) with the average 0.075 kW·h·kg-1of water removed by using the cathode net.