【作者】 尹方娜；

【导师】 李惠萍； 吴一峰；

【作者基本信息】 郑州大学 ， 化学工程， 2012， 硕士

【摘要】 赤泥是氧化铝工业冶炼过程排放的碱性固体废弃物,含有多种金属氧化物活性成分、有价金属等,同时含有4%-9%的(Na2O+K2O)及灼碱成份,其碱性强而难以得到有效利用。随着铝工业的快速发展,赤泥排放量急剧增长,带来的环境污染及其综合利用问题倍受关注。本研究任务来源于河南省重大公益科研项目,旨在降低赤泥中碱含量,使其在建材、农业等领域得到资源化利用。在前期赤泥脱碱小试成功的基础上,利用自行设计安装在中国长城铝业公司的工业化装置进行了放大试验,对实验室最佳脱碱工艺条件进行了验证,获得较佳的放大工艺条件。采用铝土矿化学分析方法、XRD、筛分法及SEM等分析手段对脱碱前后赤泥的组成和物相特征进行了全面分析对比；并对脱碱后赤泥用于硅肥生产进行了初步研究,为实现脱碱赤泥的农业规模化应用奠定基础。本文选用PC400×300锤式破碎机、振动筛(筛网孔径5mm)、MQG900×2100型单仓湿式溢流型球磨机、DU0.8/500-A型橡胶带式真空过滤机等设备,采用一段连续进料球磨、二段加酸连续进料球磨工艺流程,进行了烧结法赤泥脱碱试验研究。结果表明,赤泥料浆的固含量对球磨效果影响不大,但针对本试验装置,采用固含量为30%料浆比较适宜。在固含量为30%的赤泥料浆中,加入酸(按从原赤泥中脱除3.81%Na2O所需的硫酸计量)脱碱,脱碱后赤泥料浆经过滤、洗涤、烘干,Na2O含量降低了51.44%,K20含量降低了38.06%,脱碱效果较好,基本达到了预期目标,日处理赤泥量在10-15t。此外,采用此工艺对拜耳法赤泥进行了探索性脱碱试验研究,结果表明,拜耳法赤泥脱碱后Na2O含量仅降低了25.04%,K20仅降低了12.29%,没有烧结法赤泥脱碱效果好。此外,通过球磨机的球磨细化,赤泥颗粒的形态结构发生了变化,活性增加。对脱碱后赤泥进行XRD分析发现,其活性硅和活性钙总含量可达50%以上,且含有Mg、P、K等植物所需的养分,因此,将脱碱后赤泥制成的肥料于2011年施于信阳罗山春季水稻试验田,水稻增产约15%,具有成熟早、病虫害少、抗倒伏等特点。同时为了尽快实现赤泥硅肥的产业化,保证产品质量,规范赤泥硅肥市场,促进其健康快速的发展,初步制订了赤泥硅肥企业标准。最后,对脱碱中试试验结果进行了经济评价,采用此生产装置,年处理赤泥量可达54753吨,按照每年处理赤泥5000吨,赤泥加入量为70%生产硅肥,年销售硅肥量7000吨,800元/吨,年净利润为259.07元,具有良好的经济效益和工业应用价值。同时,也为实现赤泥规模化应用提供了理论基础和技术依据。更多还原

【Abstract】 Red mud is the alkaline solid wastes discharged from alumina during smelting process, in addition to contain a variety of metal oxides, valued metals and other active ingredients, while also containing4%-9%(Na2O+K2O) and ignition loss, its strong alkaline and is difficult to be effectively utilized. Along with the rapid development of aluminum industry, the amount of the red mud has increased dramatically which bring about environmental pollution and comprehensive utilization issues concerned. The study comes from Henan province major commonweal scientific research project, aimed at reducing the content of alkali in red mud, so that resource utilization in building materials, agriculture and other fields.The study of early lab trials in the red mud dealkalization process was successful, on the basis of this, designed and installed the industrialization of the enlargement test device in the Great Wall of China Aluminum Corporation,verified the optimal conditions of dealkalization process on laboratory tests, to obtain better amplification process conditions.The methods for bauxite chemical analysis, XRD,sieving method, SEM and other means were analyzed and compared for the composition and phase characteristics of the red mud off before and after alkali.and the red mud dealkalization after for silicon fertilizer production is studied, in order to realize the red mud of agricultural scale application.This paper selects PC400x300hammer crusher, vibrating screen (screen aperture5mm), MQG900×2100Dan Cang wet overflow type ball mill, DU0.8/500-A rubber belt vacuum filter and other equipment, using a continuous feed milling, two acid continuous feed milling process, the sintering red mud off the alkali test results showed that, the red mud slurry solid content on the ball milling effect little, but for the test device, the use of the solid content of30%slurry is more appropriate.The red mud slurry solid content of30%, adding acid (from the original red mud by removing3.81%Na2O required sulfuric acid measurement) to take off the alkali, off alkaline red mud slurry after filtering, washing, drying, decreased the content of Na2O51.44%, K2O decreased by38.06%, alkali removing effect was good, basically achieved the expected goals, the amount of dealed with red mud every day was about in10-15t.In addition, the use of this technology in Bayer red mud off the alkali exploratory test.The results showed that, the content of No2O is reduced by25.04%, K2O only decreased by12.29%, alkali removing effect is not good.In addition,, through the ball mill milling thinning, red mud particle morphology was changed, greatly improving the content of active components. In the sintering red mud after the removal of alkali based on XRD analysis, the active silica and active calcium content could reach above50%, and containing Mg, P, K and other nutrients plants required, which could be directly used in the production of silicon calcium fertilizer after dry ball milling. Applied fertilizer made of red mud off alkali Xinyang Luoshan in2011spring rice experimental field, rice yield of about15%, with early maturity, fewer pests and diseases, lodging resistance and other characteristics. At the same time in order to achieve the red mud silicon fertilizer industrialization as soon as possible, guarantee of product quality, specification of red mud silicon market, to promote its healthy and rapid development, the initial formulation of the red mud fertilizer enterprise standard was made.Finally, according to the economic evaluation, the production equipment, this production unit with annual production capacity was up to5475tons, in accordance with the annual processing5000tons, the red mud addition amount about70%to produce silicon fertilizer, annual sales volume is about7000tons,800RMB/ton, the annual net profit was about2590700RMB,with good economic benefit and application value, at the same time, also for red mud achieve scale application provided theoretical basis and technical basis.更多还原