锌焙砂硫酸浸出渣中分离ZnFe_2O_4的研究

以锌焙砂为原料,经硫酸浸出后对矿浆保温沉淀固液分离后进行高温磁力搅拌水洗,过滤烘干筛分后加入添加剂固相氧化焙烧进行粗提纯,对粗提纯产品筛分产物加入添加剂高能球磨机械活化后固相焙烧进行精提纯,并对产品进行粒度分析、XRD分析及EDS分析。结果表明,提纯产品中铁酸锌含量高达98%,产品主要集中于0.240~3.802μm、3.802~17.378μm、17.378~138.038μm三个粒级,分别占41.83%、36.70%、21.47%。粒级越小,粒度分布越大,-20μm粒级达到80%。产品形貌已经具有一定的粉体性状,经进一步的细化和均匀化等处理,有望制备出高性能的铁酸锌特性材料。     

石英中杂质矿物赋存状态及纯化研究

利用光学显微镜、电子探针、电感耦合等离子发射光谱等测试手段,对江苏某公司块状石英进行了杂质矿物赋存状态及分离纯化研究。结果表明:赋存于石英中杂质元素主要为Al、Na、Ca、Fe、Li、K、Ti;杂质矿物多为原生矿物包裹体,且主要以小于20μm的岩盐和小于120μm的白云母形式赋存于石英晶体界面间。其中Na主要以岩盐形式存在;元素F、Mg、K、Ti、Mn、Fe、Al主要赋存在白云母中,尚有一部分元素Al以类质同象形式取代石英晶格中的元素Si;元素Ca和部分S以氧化物的形式存在;Ba和另一部分S赋存在重晶石中;Cu、Zn共生形成氧化矿。经焙烧,水淬,碱浸出和混合酸浸出,可分离纯化制备出99.991wt%的高纯石英。     

镍钴富集物经电炉还原制备出的粗镍电解净化工艺研究

对镍钴富集物采用电炉还原制备出的粗镍开展了电解净化工艺扩大试验。结果表明,阴极电流效率达98.5%,粗镍阳极溶解的电流效率达85%,获得的电镍产品物理状态良好,表面光滑,化学成分达到Ni 9999电镍国家标准。粗镍阳极电解的槽电压为1.8~2.2 V,电流密度为220 A/m2,电耗为吨镍1 850 kWh左右。经过中和除铁、硫化除铜、氯气除钴、离子交换除锌处理后的阳极液可直接返回到粗镍电解作为阴极液使用。     

湿法炼锌锑盐净化工艺锌粉单耗控制措施

云锡文山锌铟冶炼有限公司湿法炼锌工艺采用锑盐净化法净化中上清液,该工艺中,锌粉单耗是最为重要的经济技术指标,每增加1 t锌粉消耗,增加的成本约为6000元。目前,国内生产吨锌锌粉单耗普遍为50~60 kg/t,该公司通过采取控制中上清液质量及供应、溶液p H值、反应温度、反应时间、锑盐加入量、锌粉粒度,及精细化操作等措施,将锌粉单耗由60 kg/t左右降至48 kg/t左右,节约生产成本达700多万元,而且新液一次合格率、新液质量等指标明显提升,经济效益显著,其经验可为湿法炼锌企业提供一定的借鉴。     

A randomized double‐blind crossover study of indoor air filtration and acute changes in cardiorespiratory health in a First Nations community

Few studies have examined indoor air quality in First Nations communities and its impact on cardiorespiratory health. To address this need, we conducted a crossover study on a First Nations reserve in Manitoba, Canada, including 37 residents in 20 homes. Each home received an electrostatic air filter and a placebo filter for 1 week in random order, and lung function, blood pressure, and endothelial function measures were collected at the beginning and end of each week. Indoor air pollutants were monitored throughout the study period. Indoor PM_2.5 decreased substantially during air filter weeks relative to placebo (mean difference: 37 μg/m³, 95% CI: 10, 64) but remained approximately five times greater than outdoor concentrations owing to a high prevalence of indoor smoking. On average, air filter use was associated with a 217‐ml (95% CI: 23, 410) increase in forced expiratory volume in 1 s, a 7.9‐mm Hg (95% CI: ?17, 0.82) decrease in systolic blood pressure, and a 4.5‐mm Hg (95% CI: ?11, 2.4) decrease in diastolic blood pressure. Consistent inverse associations were also observed between indoor PM_2.5 and lung function. In general, our findings suggest that reducing indoor PM_2.5 may contribute to improved lung function in First Nations communities.     

ACTIFLO(R)技术用于海水净化处理的问题及解决方案

ACTIFLO(R)微砂加重絮凝斜管高效沉淀技术具有沉淀速度快、处理效果好、耐冲击负荷能力强和占地面积小等特点,目前被广泛应用于淡水净化领域.针对ACTIFLO(R)技术应用于我国东南沿海某电厂海水净化处理中出现的藻类繁殖与附着、斜管局部塌陷和斜管跑砂等问题,在分析问题成因的基础上,提出了相应的解决方案,以期有利于该技术的不断完善.     

净化空调系统在设计施工过程中的控制要点

随着高新技术的发展,对生产环境的洁净要求也越来越严格,净化空调的应用越来越广泛。该文在阐述洁净等级的划分之后,根据实际经验提出净化空调系统设计存在的问题,并分析了系统施工过程应注意的问题。     

液化天然气站场的技术进展

以液化天然气应急储备调峰站为例,从天然气净化、液化、液化天然气储存、气化等方面探讨液化天然气的技术进展。     

原水预臭氧化对常规处理工艺的影响

杭州南星水厂的原水经预臭氧处理后,砂滤池除铁、锰作用得以加强并发挥了生物除氨氮作用,但反冲时滤砂难以洗净,池壁还滋生了青苔;混凝效果得到强化,矾耗降低.通过生产性试验分析了原水预臭氧化对常规工艺的不利影响,认为原水由预氯化变为预臭氧化后,生物砂滤池宜改为气水反冲洗方式,斜管沉淀池和滤池宜采用遮阳方法防止池内滋生藻类,另外从成本方面考虑,用投加臭氧来降低矾耗是不经济的.     

Flue gas cleaning by periodic absorption

Simulations and designs are presented of conventional and periodic SO₂ absorption from exhaust gases using salt water as absorption solvent. Operating conditions resemble those of a maritime operation, involving relatively small amounts of SO₂, so the separation is in the linear region. The advantages of periodic operation, as already demonstrated for conventional distillation remain valid for absorption processes: Less tall towers, than staged towers are possible, or substantially less salt water is required for the process employing periodic cycling.