实时在线颗粒分析技术在选矿行业全面应用.ppt

,实时在线颗粒分析技术 在选矿行业中的应用,梅特勒-托利多 技术应用顾问：郑 乾 cathy.zheng +139-1741-4182,2,梅特勒-托利多和您,我们殷切地期望成为您精密仪器解决方案的唯一供应商。,全球著名纽约上市公司 11200名员工 年销售额超过23亿美金,梅特勒-托利多集团,3,实验室,实验室,4,梅特勒-托利多 实时在线颗粒分析技术,梅特勒-托利多是原位条件下监控和测量颗粒和液滴的世界领导者 梅特勒-托利多在颗粒体系表征方面拥有超过25年的革新技术 我们全球的应用顾问团队具有超过2500台的实际安装应用经验，主要支持结晶、乳化、悬浮、选矿等多方面的颗粒及多相体系的应用 全世界超过 5000 名的科学家和工程师使用了该项技术,redmond, washington, usa,5,6,6,目录,实时在线颗粒分析技术介绍 应用案例,7,pvm 技术 颗粒录影显微镜技术 particle video microscope 显微镜质量、实时在线记录颗粒的图象信息 颗粒测量范围从2微米至1毫米,fbrm 技术 聚焦光束反射测量技术 focused beam reflectance measurement 在当前工艺条件下，实时原位在线追踪颗粒和液滴的变化情况 颗粒测量范围从 0.5 微米至 3 毫米,10 m 液滴,实时在线颗粒分析技术,7,从实验室到工厂的安装,基于探头的技术，不需要取样，不需要样品制备 针对颗粒体系瞬间实时响应工艺的变化 安装于10ml 至 20,000 l，管道、高压、危险、恶劣的环境中,8,pvm 技术,没有额外照明的要求 探头由耐化学腐蚀的材料制成 （哈氏合金alloy c22及蓝宝石窗口） 紧密的焦平面所获得高精度的图片，将背景颗粒的影响减到最少 即使在快速移动的流体中，也能获得清晰的图片而不会产生模糊,蓝宝石窗口,照明透镜系统,物镜,ccd,导管,ccd camera,9,在极端条件下高精度的图像,pvm 能在极端条件下获得高精度的图像信息 : 在特别粘稠或不透明的体系下，或者 在极端低或者非常高的温度和压力下 此时，不能取样,pvm 增强型视窗下原油中的水,pvm 测量原油中的气体水合物,10,11,有机晶体,12,pvm 立刻揭示聚结过程,在线 pvm 图像：,离线 显微镜图像： 之后： 过滤 干燥 制样,the use of in situ analytics for crystallization process development brian osullivan, ph.d. thesis, university college dublin, 2005,crystallization endpoint,crystallization midpoint,13,13,fbrm 聚焦光束反射测量仪,fbrm 是一个定量化的测量工具，使化学家或工程师迅速将颗粒体系的动态变化同工艺条件相联系。 在原位工艺条件下，追踪颗粒及液滴的变化程度和变化速率 fbrm 能直接测量颗粒的粒径、形状及数量 运用在线数据能帮助理解并优化动态过程 无需取样 固含量达到70% 实验室或者工厂环境 透明或者不透明的料液中 从亚微米至毫米,实验室,中试及工厂,管道,fbrm 测量方法,fbrm 在线探头的剖视图,pvm 图像说明 fbrm 探头 窗口看到的情况,安装于流体中的探头,14,15,fbrm 测量方法,pvm 图片表示 fbrm 探头 窗口观测到的情况,放大视图,fbrm 测量方法,path of focused beam,enlarged view,fbrm 每秒钟测量数千个弦长，从而形成弦长分布,放大图,聚焦光束的路径,16,在线颗粒分布以及趋势变化,不加权分布,不需要改变条件就能实现亚微米至毫米级的测量 按照用户自定义的粒径范围进行随时间趋势统计 无需校准就能测量小颗粒和大颗粒,17,18,冷却速率对小颗粒产生的影响,fbrm 立刻揭示第二阶段冷却斜率增加，产生更多小颗粒（二次成核） 较短批次时间需要同之后的较长过滤干燥时间达到平衡 （冷却速率快，批次时间较短，但小颗粒更多，过滤干燥时间更长） 设计颗粒分布能确保最有效的结晶过程,冷却速率增加,小颗粒增加,冷却结晶 1l 规模 搅拌 - 400rpm 在80c下饱和溶液,过程理解,风险管理,工艺改进/设计空间,19,如何定量确定颗粒分布的变化？,更多小颗粒,通过研究相关颗粒分布定量揭示不同工艺之间的差异,20,将颗粒分布同后续工艺相关联,更多细颗粒,21,将颗粒分布同后续工艺相关联,更多细颗粒,22,22,目录,实时在线颗粒分析技术介绍 应用案例（csiro, australian ）,fbrm&pvm在首钢水厂尾矿处理中的应用,矿石经过选别之后，将有大量尾矿产生，尾矿颗粒极细，多为泥浆状，难以沉淀，难以脱水。,23,尾矿沉淀池使尾矿水在池中进行沉淀，以达到澄清的目的。尾矿水往往呈胶状，为了使尾矿水很快地澄清，可加入凝聚剂，以加速颗粒的沉淀。,优化尾矿沉降工艺,24,在线监测不同粒径颗粒的凝聚过程 提高沉淀分离的效率 优化工艺适用最少的絮凝剂 降低设备规模,luke kirwan, aughinish alumina limited,高岭土作为凝聚剂,尾矿泥浆中加入规格为2% wt/v的高岭土作为凝聚剂。 不同加入量的pvm图像,25,8 g t-1,15 g t-1,30 g t-1,100 m,没有加入高岭土,高岭土作为凝聚剂,尾矿泥浆中加入4.5wt%高岭土悬浊液为凝聚剂。 fbrm监测加入不同量的高岭土的结果对照图。,26,investigating bauxite residue flocculation by hydroxamate and polyacrylate flocculats utilizing the focused beam reflectance measurement probe,27,cathy zheng march. 2013,luke j.kirwan,int. j. miner. process. 90 (2009) 7480,利用fbrm探头研究加入异羟肟酸和聚丙烯酸酯絮凝剂铝土矿残渣的絮凝过程,introduction: bauxite residue flocculation,extraction of alumina from bauxite generates large volumes of residue (red mud). in gravity thickener key performance factors: underflow density底流密度, throughput, and overflow clarity 溢流澄清度.,28,flocculants,(a) schematic representation of the repeat monomer unit within polyacrylate聚丙烯酸酯 flocculant (b) the incorporation of the hydroxamate异羟肟酸 functionality into an anionic polyacrylamide 阴离子聚丙烯酰胺 flocculant.,29,introduction: fbrm,settling tests, measure: 1) the rate of decent of the mudline formed泥水分界线形成的速度; 2) the clarity of the supernatant liquor in batch cylinder 母液澄清度 from this measurement, properties of the aggregates formed can be inferred fbrm: offers the potential to measure aggregate size directly fbrm is the only tool that will give a real-time, in situ indication, be shown to be a very useful tool in the study of mineral and process flocculation (e.g. hecker et al., 1999; de clercq et al., 2004). chord length distribution differs from particle size distribution square-weighted distribution is a more accurate representation of volume-weighting (heath et al., 2002). conventional sizing instruments, such as the malvern mastersizer.,30,introduction: fbrm,after flocculant addition there is an increase, followed by a peak, and then a gradual decay. the mean square-weighted chord length achieved from flocculation is proportional to the measured settling rate (heath et al., 2006). the decay behaviour is indicative of aggregate break-up caused by the continually applied mixing to the system. the rate of decay has been found to be inversely proportional to the resistance of the aggregates to breakage. a very small rate of decay indicates strong aggregates, or additionally a high rate of dynamic re-flocculation (blanco et al., 2002). fbrm has been integrated into this flocculation study to examine the comparative performance of process hydroxamate and polyacrylate flocculants on bayer process bauxite residue slurry. the study has focussed on clarity and aggregate strength as key performance indicators.,31,fbrm data focused on aggregate strength,after flocculant addition there is an increase, followed by a peak, and then a gradual decay. the mean square-weighted chord length achieved from flocculation is proportional to the measured settling rate (heath et al., 2006).,32,the decay shows aggregate break-up caused by mixing. the decay is an exponential function (alfano et al., 1999). the rate of decay is inversely proportional to the resistance of the aggregates to breakage. a very small rate of decay indicating strong aggregates, or additionally a high rate of dynamic reflocculation.(blanco et al., 2002).,methods,with settling test: 250ml, equilibrate 3 min, flocculant dose, stop stirrer; after 5min, 20ml sample determined gravimetrically without settling test: 150ml, 95c, equilibrate 10 min, flocculant dose for a further 10min. if add starch, added 7.5 min after experiment started.,33,viscosity-concentration,hydroxamate flocculant: hx300 polyacrylate flocculant: 9779,34,at a 9779 concentration of 0.06 % and a hx300 concentration of 0.13 %, equivalent viscosities.,viscosity and hence mixing issues are not a concern for the starch solution, therefore in experiments where starch was used, it was added undiluted.,fbrm,35,the decay shows aggregate break-up caused by mixing. the decay is an exponential function (alfano et al., 1999). the rate of decay is inversely proportional to the resistance of the aggregates to breakage. a very small rate of decay indicating strong aggregates, or additionally a high rate of dynamic reflocculation.(blanco et al., 2002).,flocculation study,there is an increase in the max. size with increasing flocculant dosage and this corresponds with a decreasing trend in the 1 5 m fine counts. however, it can also be seen that several experiments have been repeated and reproducibility was often poor. however, such variations are inevitable with plant slurries involving digestion and supersaturation.,36,fbrm from table 1,on the same general curve, regardless of flocculant added, agitation intensity, and whether starch was added or not. the addition of starch would appear to improve the performance of the 9779 polyacrylate flocculant.,37,settling test,figure 5: the relationship between the gravimetric solids left behind in the supernatant after settling for 5 mins with (a) the fbrm 1 5 m fine counts/s and; (b) the maximum mean square-weighted chord length. hx gave visibly much larger aggregates, which exhibited faster settling, and better fines capture in comparison to 9779 hx offer a greater capture efficiency,38,supernatant solids,hx300 flocculation were much harder to and appeared more red in coloured compared to those from 9779 flocculation. encouraging,39,sem images,figure 6: (a) sem image of the thickener overflow solids from the thickener utilising hx300 feedwell flocculation and (b) the thickener using 9779 feedwell flocculation.,40,edx能量色散x射线光谱仪,41,figure 7 shows that the solids from the hx300 treated thickener have relatively much higher amounts of iron, but relatively less amounts of titanium, calcium, and silicon.,aggregate strength,42,this aggregate breakage has been examined by fitting an exponential y = co + a.exp(-x/tb),co is the final size; a + co the initial size; 1/tb the rate of decay. tb indicates a robust aggregate structure,aggregate strength,43,the aggregates formed are more robust the use of starch with 9779 did not appear to have an influence,aggregate strength,44,industrial application,the key difference was found to be the way the aggregates developed post-shear, with hydroxamate flocculation exhibiting a greater degree of post-shear flocculation 后剪切絮凝.,45,剪切絮凝是利用对矿浆进行较强烈搅拌而产生的剪切力和捕收剂在矿粒表面吸附所产生的疏水键合力，使微细矿粒形成絮团，进行分离回收的浮选方法。,co-flocculation of bauxite residue with polyacrylate and hydroxamate flocculants is to be examined in further detail in a subsequent publication.,conclusion,fbrm has proved to be a very powerful tool for investigating and comparing the flocculation performance of process hydroxamate and polyacrylate flocculants with bayer process bauxite residue slurry. the key difference in polyacrylate and hydroxamate flocculation is the way the aggregates develop post-shear, with hydroxamate aggregates exhibiting a greater degree of post-shear aggregation.,46,结论,fbrm 可以实时监测矿浆的粒度大小以及粒度的正态分布。 fbrm 和pvm可以帮助用户揭示凝聚剂对细小颗粒的凝聚过程。 fbrm 可以监测不同的工艺