优化烧结法工艺的研究

通过对烧结法工艺过程中碳分母液进行彻底碳分及回收物的利用的试验研究 ,指出该措施的实施既可减少由碳分母液返回配料所造成的氧化铝回头 ,又使碳分母液的蒸发浓度提高到 2 30g L以上 ,是优化烧结法工艺的新途径     

优化烧结法工艺的研究

通过对烧结法工艺过程中碳分母液进行彻底碳分及回收物的利用的试验研究，指出该措施的实施既可减少由碳分母液返回配料所造成的氧化铝回头，又使碳分母液的蒸发浓度提高到230g/L以上，是优化烧结法工艺的新途径。     

提高间断碳分氢氧化铝的粒度

通过碳酸化分解机理介绍了烧结法生产氧化铝间断碳分分解工艺过程 ,针对氧化铝行业发展对产品粒度的要求 ,提出了添加晶种间断碳分分解工艺提高氢氧化铝产品粒度的工艺技术     

拜耳法生产工艺中综合除碳技术的研究及应用

目前铝土矿资源匮乏，各氧化铝厂使用铝土矿种类复杂、品位低下、矿石中碳含量偏高等，导致单位能耗增加、产能降低，同时氧化铝生产中系统碳酸钠累积，也对溶出、沉降、蒸发等多个工序造成不利影响，排碳除杂工作迫在眉睫。目前该氧化铝厂主要采取蒸发强制效提浓、排盐苛化工艺去除系统碳酸钠，但该工艺流程复杂、能耗高、排碳成本高且排碳能力有限，通过技改沉降二次洗液添加石灰乳进行苛化同时串联立式叶滤机综合除碳工艺，提升系统综合除碳能力，拓宽铝土矿使用种类，进一步降低生产成本及能耗。     

降低拜耳法氧化铝生产系统碳碱浓度的探索与实践

氧化铝系统中的碳碱被视为无效碱,长期在流程中积累,增加了单位能耗,碳碱达到平衡浓度时,以固体析出,碳碱浓度过高会对溶出、沉降、分解、蒸发等多个工序造成不利影响。文章主要对拜耳法氧化铝生产系统碳碱浓度升高的原因及危害,以及如何有效降低系统碳碱浓度进行了探索与实践,总结了降低系统碳碱浓度的有效经验,对其他采取拜耳法工艺生产氧化铝的企业有良好的借鉴作用。     

提高联合法氧化铝产品粒度和强度工艺技术探讨

本文介绍了种分一段法和二段法生产砂状氧化铝的工艺技术特点，以及连续碳分生产砂状氧化铝分解技术特点．并对提高粒度和强度的机理进行讨论．然后提出把联合法的种分和碳分工艺有机结合起来以提高产品氧化铝拉度和强度的工艺技术方案。     

碳分氢氧化铝粒度变化规律的研究

目前,烧结法生产砂状氧化铝的粒度问题日益受到重视.而砂状氧化铝的粒度主要由碳分氢氧化铝粒度决定,所以研究碳分氢氧化铝粒度变化规律具有重要意义.文章运用数学方法,对碳分试验所得数据进行分析,得出氢氧化铝粒度变化诸因素的影响程度大小,确定了合理的工艺条件.     

强化烧结法工艺的途径

分析了烧结法系统中影响氧化铝产量及成本的因素 ,指出碳分工序是影响烧结法经济指标的关键 ,提出采用深度碳分技术强化烧结法工艺。通过试验充分阐述了该技术在氧化铝生产中实施的可行性     

深度碳分技术在烧结法生产中的应用

本文通过剖析烧结法系统中影响氧化铝产量及成本的薄弱环节,指出碳分工序是影响烧结法经济指标的关键,从而提出了采用深度碳分技术来优化烧结法工艺,并阐述了该技术在氧化铝生产中实施的可行性。     

强化烧结法工艺的途径

分析了烧结法系统中影响氧化铝产量及成本的因素，指出碳分工序是影响烧结法经济指标的关键，提出采用深度碳分技术强化烧结法工艺。通过试验充分阐述了该技术在氧化铝生产中实施的可行性。     

Carbonation Behavior Assessment of RH Slag Batch after Aqueous Extraction at Environmental Pressure

In order to assess CO₂ sequestration amount and carbonation degree for RH slag at surrounding pressure, carbonation process of RH slag batch in lab is investigated, and the parameters of carbonation degree and CO₂ sequestration amount are the targets, and the relationship between both and relevant factors, such as CO₂ flow, gas bubble size etc. is originally discussed. The carbonation degree increases when temperature increases before 60 °C, then decreases. Particle size has a positive effect on carbonation degree, and carbonation degree for 0.5 L/min is bigger than those for 0.1 L/min and 1.0 L/min. When small gas bubble generator is adopted, carbonation degree and CO₂ sequestration amount is improved. The maximum carbonation degree and CO₂ sequestration amount is 34% and 178.65 g/kgslag, respectively when 38 μm RH slag batch is carbonated for 90 min at 60 °C under the conditions that CO₂ flow is 0.5 L/min and bubble size equals 5 mm. CaCO₃ and MgCO₃ phases exists through XRD analysis, showing that carbonation process is effective. Carbonation degree model is established assuming carbonation reaction occurs on the active surface of RH slag batch. This model fits very well by comparison between experimental results and model results.     

低浓度碱介质中钢渣碳酸化反应特征

 钢渣碳酸化是一种CO2矿化利用的有效方法。通过添加低浓度碱,可有效提高钢渣碳酸化转化效率。围绕低浓度碱介质中钢渣碳酸化过程,系统研究了搅拌转速、低浓度碱浓度、反应温度等工艺条件对钢渣碳酸化转化效率的影响。在搅拌转速为450 r/min,碱浓度为20 g/L,反应温度为70 ℃等优化工艺条件下可实现钢渣碳酸化转化效率为49.72%,是传统水介质体系的1.8倍以上,且反应条件温和,介质可循环利用。进一步开展了钢渣碳酸化反应动力学研究,结果表明钢渣碳酸化反应为内扩散控制,计算得到表观活化能为22.48 kJ·mol－1。     

Theoretical Foundation of Carbonation Pellet Process for Ferrous Sludge Recycling

 For the recycling of ferrous sludge from steel industry, the carbonation pellet process should be considered as a “green” process, since no impurities are added as well as CO2 can be sequestrated and consumed. Through the thermodynamic calculation, the carbonation reaction can occur spontaneously and is an exothermic reaction. Based on the kinetic analysis through unreacted core model, the interfacial chemical reaction was the rate controlling step in the initial fast stage of carbonation, and the CO2 diffusion through the CaCO3 product layer was the rate controlling step in the following extremely slow stage. For the carbonation bonded mechanism, the pellet strength was gained by the formation and growing of CaCO3 product layer. Since the interfacial chemical reaction was the critical stage of the entire carbonation process, the emphasizes should be focused on the improvement of sorbent activity and the optimization of process parameters, such as pore structure, pore surface area, and total pressure, CO2 partial pressure, reaction temperature, etc to accelerate the reaction rate and to improve the quality of carbonation pellets.     

钢渣碳化砖的碱激发-碳化协同作用机制

摘要：以钢渣为原料,标准砂为骨料,碳酸钠为碱激发剂,基于碱激发 碳化协同作用制备钢渣碳化砖。采用X射线衍射、热重/差示扫描量热分析、压汞法以及扫描电子显微镜分别对试样的物相组成、孔隙率以及微观形貌进行表征。通过对比研究“碱激发”、“碳化”以及“碱激发+碳化”作用对试样强度、产物组成、孔隙率以及微观形貌的影响,对碱激发 碳化协同作用机制进行深入探讨。结果表明,碳酸钠可激发钢渣胶凝活性,生成薄片状水化硅酸钙（C-S-H）凝胶,为试样提供初始性能。碳化过程中生成的CaCO3等反应产物对试样具有“填充效应”,这是试样强度性能提高的主要原因。碱激发过程中生成的C-S-H凝胶为碳化反应提供碳化源,促进碳化反应的发生;碳化反应利用碱激发反应产物C-S-H凝胶为碳化源,生成CaCO3等反应产物,使基体致密程度提高,从而使试样性能得到进一步优化。     

不同温度下精炼渣碳酸化微观结构变化

为了研究不同反应温度条件下精炼渣矿相成分在碳酸化过程中微观结构特征变化,在不同碳酸化反应温度20、40、60、80℃下,采用X射线衍射(XRD)、扫描电镜(SEM)、热重(TG-DTG)、29Si固体核磁共振等测试方法分析了精炼渣碳酸化特征变化.结果表明,随着碳酸化反应温度的升高,精炼渣与反应产物CaCO3的粒径逐渐增...     

高铝粉煤灰高效增值利用新技术

针对当前高铝粉煤灰综合利用技术难题,提出了高铝粉煤灰预脱硅烧结法提取氧化铝新工艺。新工艺取消了铝酸钠溶液碳酸化分解工序,改为全种子分解工艺。通过合成技术优化,采用高苛性比合成技术,种分母液与预脱硅后的硅酸钠溶液可制备出合格的洗涤用4A沸石。生产过程中,通过补充少量水玻璃用于调节氢氧化铝和4A沸石两种产品的产出比例,可以较好地保障生产系统物料平衡。新工艺取消了石灰炉、氧化铝焙烧炉、铝酸钠溶液碳酸化分解和深度脱硅工序,工艺能耗降低,废渣排放量减少,碳排放量降低。此技术生产流程相对简单、技术可行、经济性好、竞争力较强。     

Effect of impurity ions on preparation of novel saponifier for rare earth extraction

Magnesium bicarbonate,prepared by the carbonation of magnesium hydroxide slurry,was used as a novel saponifier to eliminate the ammonia nitrogen pollution in the rare earth extraction separation process.The effect of impurity ions introduced by system on the carbonation reaction of magnesium hydroxide was studied in the work.The results showed that the presence of Ca2+ could lead to side reactions so as to reduce the conversion rate of magnesium hydroxide,and a small number of rare earth ions would have great influence on the carbonation reaction.What’s more,there was no influence on carbonation reaction with the low concentration of Na+or Mg2+,the conversion rate of magnesium hydroxide could reach above 96%.This paper showed a practical theory which could provide scientific guidance for the preparation of novel saponifier in rare earth extraction separation process.     

Study on preparation and application of novel saponification agent for organic phase of rare earths extraction

In view of the problem of ammonia-nitrogen wastewater pollution in rare earths extraction and separation, the novel saponification agent of organic phase, which is magnesium bicarbonate solution, was prepared with the natural rich and cheap dolomite as raw material through carbonation process. The behavior and purification of main impurities ions in the carbonation process as well as the application effect of the novel saponification agent in the extraction and separation was researched. The results showed that the concentration of Fe, Al, Si impurities ions was less than 5 ppm in the saponification agent through the development of effective removal technology, respectively. When the novel saponification agent was used in the extraction and separation, magnesium utilization rate was more than 95%, and rare earths extraction rate above 99.5% has achieved. Therefore, the technology could replace ammonia-water to saponify the organic phase in rare earth extraction and separation process.     

LF精炼渣碳酸化过程Ca赋存状态转变

为提高LF精炼渣资源化利用效率,对精炼渣碳酸化过程中Ca赋存状态转变进行了研究。通过碳酸化实验确定了温度为20℃,液固比为5,通气量为600 mL/min,转速为700 rad/min,粒径小于88μm时碳酸化效果最好,并探究了不同pH条件下Ca^2+、HCO3^-、CO3^2-的浓度变化。在此基础上,利用XRD、SEM、TG-DTA、FT-IR等方法对碳酸化前后精炼渣进行了表征分析。XRD分析表明,f-CaO、Ca2SiO4、Ca3Al2(SiO4)3衍射峰强度减弱,碳酸化后主要产物为CaCO3;DG-DTA分析表明,碳酸化产物在600~800℃失重率达13.35%;SEM分析表明,生成的CaCO3颗粒聚集附着在精炼渣颗粒表面;FT-IR表明,碳酸化后产生大量碳酸盐,并多为方解石晶型。     

含铁粉尘再资源化利用与碳酸化球团工艺

钢铁生产过程的各类含铁粉尘具有较高的再资源化利用价值,其回收利用工艺影响生产效率、资源消耗、产品质量等.综合比较认为,碳酸化球团-转炉工艺将含铁粉尘与CO2回收利用有机结合,有望成为钢铁工业含铁粉尘再资源化利用的"绿色"工艺.理论分析表明:含铁粉尘碳酸化球团工艺从热力学角度不仅是可行的,而且理论上可以通过工艺参数与装备设计优化,实现回收利用过程"零"能耗,甚至"负"能耗;从动力学角度,通过提高CO2分压、合理优化反应温度等措施,可加快碳酸化反应速率,提高Ca0转化率和成品球团强度;碳酸化冷固结球团用作转炉造渣剂,可降低转炉炼钢消耗,提高钢质量,是其理想的利用途径.