酸浸法从煤矸石中浸取氧化铝的最佳因素

研究了酸浸法对煤矸石组分的浸取效果,利用正交试验确定了酸浸法从煤矸石中浸取氧化铝的最佳因子,并讨论了各因子对氧化铝浸出率的影响,确定了矸石粒度0.15 mm,煅烧温度780℃,煅烧时间2 h,盐酸质量分数15%,液固比6∶1,浸取温度50℃,浸取时间3 h为最佳浸出条件,并得到在此条件下氧化铝的浸取率为67.4%.     

NH_3-(NH_4)_2SO_4体系浸析PCB污泥中铜的研究

利用NH3-(NH4)2SO4体系,对印刷电路板(printed circuit boards,PCB)生产过程中产生大量的含铜污泥中的铜进行浸析。对PCB污泥中重金属的质量分数进行了测定,其中铜在污泥中的质量分数为33.500%,其余金属质量分数较小。重点探讨了氨-硫酸铵浓度及pH、浸析时间、液固比、温度等条件对浸析率的影响。NH3-(NH4)2SO4体系对PCB污泥中铜浸析的最优条件为氨、硫酸铵浓度分别为3.0mol/L和1.5mol/L,液固比为20mL/g,浸析时间为180min,浸析温度为25℃。在最优条件下进行了浸析应用试验,结果表明铜的浸析率可达到97.5%,此方法的相对标准偏差(relative standard deviation,RSD)为0.63%。     

PEG6000辅助微波-稀H_2SO_4溶液预处理花生壳工艺优化研究

在非离子表面活性剂PEG6000存在的情况下,利用微波-稀H2SO4溶液对花生壳粉进行预处理,考察稀H2SO4溶液质量分数、微波功率、加热时间和PEG6000添加量对预处理的影响.结果表明,最佳预处理工艺为:稀H2SO4溶液质量分数为4%,微波功率为640 W,加热时间为45min,PEG6000添加量为8%.在此条件下,还原糖含量为23.67 mg/mL.     

锆钛铟超强酸的制备及催化酯化柠檬酸三乙酯

用共沉淀法,以铟(In)的质量分数、焙烧时间、焙烧温度为因素,通过L9(34)正交试验制备SO24-/TiO2-ZrO2-In2O3固体超强酸,以柠檬酸三乙酯合成考察了各因素对固体超强酸度的影响。结果表明,固体超强酸SO24-/TiO2-ZrO2-In2O3的最佳制备条件是In质量分数为1.5%,焙烧温度550℃,焙烧时间4h,其酯化率达97.8%。并用XRD、SEM、FTIR对固体超强酸进行了表征,加入In后,固体超强酸体积变大、膨松,可吸附更多的SO24-,使超强酸的酸性更强;固体超强酸中的TiO2由无定型结构转变为锐钛矿晶型结构,并随着焙烧温度的增加,TiO2的衍射峰逐渐变得尖锐。对酯化产物进行了红外光谱表征和折光率测定。     

H_2SO_4-NaCl体系下硫精矿中铜的浸出

某硫精矿直接采用浮选或硫酸浸出均无法回收其中的铜,导致铜资源浪费,且影响精矿的再利用。采用NaCl为助浸剂,H2SO4浸出该硫精矿中的铜。探讨了助浸剂的种类、NaCl浓度、H2SO4体积分数、固液比、浸出温度、浸出时间等因素对铜浸出的影响。试验表明,在H2SO4体积分数为5%、NaCl浓度为0.5 mol/L、浸出温度为85℃、固液比为1∶3(g/g)时,8 h内铜的浸出率可达84.02%。动力学研究表明,在H2SO4-NaCl浸出体系下硫精矿中铜的浸出受固膜扩散控制,可以通过增加温度提高浸出剂在矿物颗粒表面的扩散速率,从而提高铜的浸出率。     

Zr(SO_4)_2/γ-Al_2O_3固体酸催化合成环己酮1,2-丙二醇缩酮

通过直接浸渍-焙烧等方法,制备了Zr(SO4)2/γ-Al2O3催化剂,以环己酮和1,2-丙二醇为原料合成了环己酮1,2-丙二醇缩酮。考察了催化剂的焙烧温度、催化剂的质量分数、原料摩尔比、带水剂体积、回流时间对反应的影响。最佳反应条件为:焙烧温度为550℃,Zr(SO4)2的质量分数为20.0%,催化剂的质量分数为5.0%,环己酮与1,2-丙二醇的摩尔比为1∶1.5,甲苯的体积为15 mL,回流时间为3 h。环己酮1,2-丙二醇缩酮的收率可达98.7%,纯度达到99.6%。     

SO_4~(2-)/TiO_2-ZrO_2-Nd_2O_3催化剂的制备及其催化合成双季戊四醇六脂肪酸酯

用共沉淀和浸渍法制备SO24-/TiO2-ZrO2-Nd2O3三元超强酸,以其为催化剂,合成双季戊四醇六辛酸酯,考察了钕(Nd)的质量分数、焙烧时间、焙烧温度对三元超强酸催化性能的影响;同时采用正交试验对制备条件进行了优化。催化剂用BET、SEM、XRD、FTIR表征,双季戊四醇六辛酸酯的结构采用FTIR表征。结果表明,加入Nd使固体酸体积变大,酸性增强,550℃时超强酸中的TiO2由无定型结构变为锐钛矿晶型结构,SO24-/TiO2-ZrO2-Nd2O3的最佳制备条件是Nd质量分数为1.5%,焙烧温度550℃,焙烧时间4h,其酯化率达92.3%。FTIR表征结果认证了产品为双季戊四醇六辛酸酯。     

页岩灰制水玻璃的试验研究

页岩灰为油页岩及其半焦的燃烧产物,可作为建筑原材料、化工填料和吸附剂等,具有一定的工程应用价值。为研究页岩灰制取水玻璃的最佳条件,分别以水玻璃模数和页岩灰中SiO2溶出率为指标,NaOH溶液质量分数、物料比（NaOH溶液与页岩灰的质量比）、碱浸时间和碱浸温度为影响因素,进行了正交试验。对正交试验结果进行了极差分析和方差分析,两种分析方法得出的结论一致。最优方案分别为NaOH溶液质量分数10％、物料比1：1、反应时间6h、反应温度100℃和NaOH溶液质量分数40％、物料比1：1、反应时间8h、反应温度100℃．经验证,最优方案的水玻璃模数和SiO2溶出率分别为4．816和94．337％,为最优试验结果。     

辉钼精矿熔盐氧化工艺研究——Na2MoO4—Na2SO4体系

对辉钼精矿在Na2MoO4-Na2SO4体系的熔盐氧化过程进行了研究,探索了不同的工艺参数对钼的转化率和脱硫率的影响。研究结果表明,在熔盐组成Na2MoO4与Na2SO4质量比为3：1,配料比为1：10（质量比）,温度为700℃,鼓风速度为1.66m/s,鼓风时间为20min的条件下,脱硫率可达99％以上;得到的熔盐经水浸和碱浸后,钼以Na2MoO4形态进入溶液,钼的总浸出率可达95.5%以上;硫以SO2的形态进入气相,烟气中的SO2体积分数可达5.4%以上,可用于制酸;含钼渣和浸出液蒸发结晶得到的Na2SO4晶体可返回再用;熔盐氧化过程采用连续操作分批加料方式,可提高生产能力。     

制备条件对SO_4~(2-)/ZrO_2固体超强酸含硫量的影响

利用硫酸钡重量法对SO42-/ZrO2固体超强酸中的硫含量进行了分析。结果表明:随焙烧温度的升高SO42-/ZrO2存在两个SO42-的快速流失温度区,并与晶相转变温度相对应。此外,ZrOCl2,H2SO4,NH3·H2O的浓度及焙烧时间等制备条件对SO42-/ZrO2中的硫含量都存在较大影响。     

Extraction of vanadium from stone coal by modified salt-roasting process

In order to reduce the pollution of Cl₂ and HCl released during extracting vanadium from stone coal by sodium chloride roasting, a modified salt-roasting process was proposed by adding calcined lime in roasting process followed by H₂SO₄ leaching. The effects of parameters including roasting temperature, roasting time, addition mass ratio of NaCl, calcined lime upon leaching rate of vanadium and curing rate of chlorine were investigated, and the effects of leaching time and leaching temperature on leaching rate of vanadium were also studied. The results show that the vanadium leaching rate and the curing rate of chlorine are 67.3% and 51.5% (mass fraction), respectively, at roasting temperature of 750 °C, roasting time of 4 h, 15% sodium chloride and 8% (mass fraction) calcined lime, leaching temperature of room temperature, and leaching time of 4 h.     

流化床燃烧中煤含灰量对灰渣形成特性的影响

为了研究煤颗粒灰质量分数对煤在流化床燃烧过程中灰渣形成特性的影响,在一台小型流化床反应炉上进行煤的灰质量分数对灰渣形成特性的实验.按煤颗粒的灰质量分数,把义马烟煤分为6个颗粒组,并选用各颗粒组的3个粒径范围的煤颗粒进行燃烧实验,研究煤颗粒的灰质量分数对底渣质量分数、底渣与飞灰中的碳量质量分数和粒径分布的影响.结果表明,随着煤颗粒灰质量分数的增加,燃烧形成的底渣质量分数增加,而煤颗粒的燃尽率和飞灰中的碳质量分数都降低.在粒径和燃烧时间相同的条件下,随着颗粒灰质量分数的增加,底渣中留在本粒径档的颗粒质量分数明显增加,而细颗粒的质量分数明显减少.而颗粒灰质量分数对飞灰的粒径分布没有明显的影响.     

Extraction of valuable metals from low-grade nickeliferous laterite ore by reduction roasting-ammonia leaching method

Nickel and cobalt were extracted from low-grade nickeliferous laterite ore using a reduction roasting-ammonia leaching method. The reduction roasting-ammonia leaching experimental tests were chiefly introduced, by which fine coal was used as a reductant. The results show that the optimum process conditions are confirmed as follows: in reduction roasting process, the mass fraction of reductant in the ore is 10%, roasting time is 120 min, roasting temperature is 1 023–1 073 K; in ammonia leaching process, the liquid-to-solid ratio is 4:1(mL/g), leaching temperature is 313 K, leaching time is 120 min, and concentration ratio of NH₃ to CO₂ is 90 g/L:60 g/L. Under the optimum conditions, leaching efficiencies of nickel and cobalt are 86.25% and 60.84%, respectively. Therefore, nickel and cobalt can be effectively reclaimed, and the leaching agent can be also recycled at room temperature and normal pressure.     

干法烟气脱硫用高效粒状脱硫剂的研究

介绍了用粉煤灰、消石灰等制备成粒状脱硫剂,在固定床脱硫装置中对粒状脱硫剂的性能进行了实验,结果表明,在固定床中粒状脱硫剂层厚度为１．６ｍ,空床气速为０．２４ｍ／ｓ,二氧化硫平均浓度约为１６００ｍｇ／ｍ＾３时,脱硫效率维持在９０％以上的运行时间为７０ｈ,床层阻力约为２５０Ｐａ／ｍ。     

磁化矿石颗粒模型及磁选过程分析

基于磁选过程中颗粒尺寸、磁场强度和磁选精矿品位三者之间的关系,建立磁化矿石颗粒模型,对其进行理论分析与计算,确定最佳磁场强度,并进行磁化矿石的磁选研究。结果表明：在配煤量4%（质量分数）,焙烧温度850℃,焙烧时间60 min,磨矿细度-0.074 mm占60%（质量分数）,磁场强度为40 mT的条件下,得到铁品位57.7%（质量分数）,铁回收率90.3%（质量分数）的铁精矿,较好地实现了铁精矿的富集和回收。     

A new process of extracting vanadium from stone coal

A new process of extracting vanadium from the stone coal vanadium ore in Fangshankou, Dtmhuang area of Gansu Province, China was introduced. Various leaching experiments were carried out, and the results show that the vanadium ore in Fangshankou is difficult to process due to its high consumption of acid and the high leaching rate of impurities. However, the leaching rate can be up to 80% and the content of V2O5 in the residue can be between 0.22%-0.25% in the process of ore fine grinding→oxidation roasting→mixing and ripen-ing→aqueous leaching→P2O4 solvent extraction→sulfiuie acid stripping→oxidation and precipitation→decomposition by heat. Also, the quality of flaky V2O5 produced by this process can meet the requirements of GB3283-87. The total leaching rate of vanadium is 70%. Also, three types of wastes are easy to treat. The vanadium extraction process is better in relation to the aspect of environmental protection than the sodium method.     

循环流化床锅炉中灰颗粒的演化特征

循环流化床(CFB)锅炉炉内的燃烧及传热与炉内床料的状态密切相关,而炉内床料主要是由燃煤含有的矿物组分经过燃烧、爆裂和磨耗过程形成的。对多家循环流化床电站锅炉选用煤种和不同部位的灰进行取样,使用可视化显微仪,获取了粒度分布和灰颗粒的微观形貌特征。根据循环流化床锅炉内灰颗粒的机械强度和耐磨性能的不同,将灰颗粒归为三类不同性质的灰,以此为基点,分别采用固定床燃烧后冷态振动筛分的方法和流化床实验台热态流化后筛分的方法,对比分析了灰颗粒在燃烧过程中的演化特征。结果表明:三类灰颗粒在不同的燃烧温度和时间的演化过程存在明显的不同。从而对循环流化床中的床料粒径分布的确定提供了理论依据。     

垃圾和煤混烧流化床焚烧炉的二恶英排放质量平衡

为了研究二恶英的生成与消减情况,引入二恶英质量平衡的方法.建立某垃圾和煤混烧流化床焚烧炉的二恶英输入、输出质量平衡方程式,并在该焚烧炉中开展了多个运行工况条件下的烟气、灰渣中的二恶英质量浓度和质量分数检测试验.研究发现,由于“记忆效应”,掺煤燃烧产生的SO2对二恶英的抑制作用有延迟现象,垃圾和煤混烧能消减原生垃圾中的大部分二恶英,使焚烧系统输出的二恶英毒性质量远小于输入的二恶英毒性质量.还对比了国内外一些垃圾焚烧炉的二恶英排放质量平衡,发现垃圾和煤混烧流化床焚烧炉毒性二恶英的环境年排放量为-495.029～4.524 mg,比国内外报道中的垃圾焚烧炉更低,在一定程度上说明该焚烧炉可从总体上有效减少二恶英排放.     

Physicochemical properties and heavy metals leachability of fly ash from coal-fired power plant

The physicochemical properties of fly ash from two kinds of coal-fired power plants were studied. Three aspects were examined: the micro-morphology, the mineral composition and the content of heavy metals. The results show that the fly ash from plants using a circulating fluidized bed are more irregular particles, while the particles from the plants using a pulverized coal-fired boiler are mainly spherical in shape. Quartz and mullite are the main crystalline phases in the ash. Clearly, both the technology and the coal used by a power plant can influence the mineral composition of the ash. The mineral composition of fly ash from a circulating fluidized bed is more complex than that from a pulverized coal-fired boiler. The quantity of elements found in the fly ash is greater than that found in the bottom ash for the same plant. Heavy metals are likely to be enriched in the fly ash. Heavy metal leachability was studied using two leaching methods. The results indicate that most of the heavy metals that leached during either batch leaching or column leaching experiments did not exceed the related maximum concentration standards. But Ni concentrations in the leachates from both batch and column tests exceed the standard. The highest excess rates in both tests were 572% and 497%, which levels might threaten the environment.     

添加剂对稻草灰熔融特性影响的实验研究

为了给生物质热化学转化中灰结渣和聚团问题的解决提供参考和依据,在小型实验装置上对稻草、稻草与添加剂混合物进行了燃烧试验.通过热力平衡计算软件选出合适的添加剂,添加剂包括Al粉、Si粉、Al2O3、SiO2、Ca3(PO4)2、CaSiO3、CaCO3、Al2(SO4)318H2O、CaSO4、CaO、(NH4)H2PO4等,通过对样品燃烧生成的底灰进行观测分析,选择较理想的添加剂(NH4)H2PO4,Al2(SO4)318H2O,CaSO4,CaO,CaCO3.理想添加剂样品底灰的XRD测试结果表明,(NH4)H2PO4可将稻草中钾转化为高熔点的K2CaP2O7;CaSO4和Al2(SO4)318H2O则可将碱金属钾以K2SO4形式固定在底灰中;CaO,CaCO3不直接与碱金属反应,但可与系统中的其它元素进行反应,促进稻草中熔融态钾的转化析出.实验结果表明,添加剂是解决由碱金属引起的秸秆灰熔融问题的有效途径之一.