硫精矿中铜钴同步浸出试验研究

以湖北大冶含铜钴硫精矿为原料,分别研究了硫精矿、硫精矿氧化焙烧渣和硫精矿氧化-还原焙烧渣中铜、钴的同步浸出行为,考察了浸出温度、浸出时间、固液比等工艺参数对铜、钴浸出的影响。结果表明,硫精矿氧化-还原焙烧渣中的铜、钴最易被浸出,浸出条件为:浸出温度70 ℃、浸出时间4 h、固液比1∶5,此时铜和钴浸出率分别为91.46%和65.84%; 采用氧化-还原焙烧-浸出-磁选联合流程处理硫精矿时,可获得铁品位62.31%、回收率68.26%的铁精矿,该工艺实现了硫精矿及焙烧渣中铜、钴、铁资源的综合回收。     

FeCl_2·2H_2O焙烧过程动力学研究

用固定床研究了FeCl_2·2H_2O焙烧过程的动力学行为,变量包括温度、物料颗粒尺寸、气流速度和气流中含水量,讨论了过程的控制步骤,估算了表观反应速率常数和表观活化能,并用热分析校核了结果.     

锌湿法冶炼渣的自热焙烧无害化处理

针对湿法炼锌常压浸出渣和氧压浸出渣（均为危险废物）组成的高硫混合渣,系统考察了自热焙烧反应的各因素（温度、硫含量等）对渣中重金属固化效果的影响,并采用BCR连续提取法研究了焙烧前后渣中重金属的化学形态分布。结果表明,在焙烧温度1 000 ℃、混合物料硫质量分数20%、空气流速1.6 m3/h、焙烧时间7 h的条件下,渣中Zn、Pb、As、Cd等毒性浸出结果均可满足国家标准,渣率可降至约70%,焙烧热处理后渣中的Zn、Pb、As及Cd均以相对稳定的残渣态为主要化学形态,为锌湿法冶炼渣的低成本无害化与减量化处理提供了理论基础。     

辉钼矿悬浮态焙烧试验研究

采用"两段式"焙烧新工艺,即利用悬浮态焙烧技术在预反应器中脱除辉钼矿精矿中的大部分硫,然后在回转窑内脱除残余硫,在试验室模拟悬浮态装置中考察焙烧温度、焙烧时间等参数对脱硫效果的影响以及钼精矿的预反应过程。结果表明,相对于焙烧时间而言,焙烧温度对残硫量的影响相对较小;在脱硫率≤80%时,绝大部分氧化钼以MoO2形式存在,不会产生MoO3大量升华损失的情况;在焙烧温度700⁷80℃、物料停留时间1780℃、物料停留时间1³s时,悬浮态焙烧技术可以实现50%以上的表观脱硫率;相对于堆积态焙烧,脱硫效率大大提高。     

花生焙炒过程中红衣对毛油品质影响的研究

将花生进行3种不同加工方式的处理(包裹红衣焙炒,焙炒后脱除红衣,脱除红衣后焙炒)后提取花生毛油,对所提取的花生毛油进行品质分析,以研究花生红衣脱除与否以及红衣脱除和焙炒的顺序对花生毛油品质的影响。结果表明:随着焙炒温度升高、焙炒时间延长,花生毛油色泽逐渐加深;花生红衣对花生毛油的色泽未造成影响;包裹红衣焙炒组具有最高的酸败风险;相同焙炒条件下,花生毛油的脂肪酸、反式脂肪酸和甘油三酯组成都无明显差异;花生毛油的脂肪酸组成、反式亚麻酸含量、甘油三酯组成均不受焙炒温度和焙炒时间变化的影响,花生毛油反式油酸、反式亚油酸含量和反式脂肪酸总量则随焙炒温度升高、焙炒时间的延长呈现攀升趋势。     

Effect of malting conditions and quality characteristics of malt and roasted malt extract from ‘acha’ grains (Digitaria exilis Stapf)

BACKGROUND: Considering the importance of malting and roasting on the quality of ‘acha’ beverages, a study was conducted to find optimum conditions for malting and the production of a high‐quality roasted extract that could be used for an ‘acha’ beverage. RESULTS: The data obtained were analysed using response surface methodology. The results revealed that the most significant (P < 0.05) malting factors that affect the response variables were the linear terms of germination time and drying temperature. However, for the extract production, the linear term of roasting temperature was the most significant (P < 0.05) factor. The quadratic and interaction terms exhibited significant (P < 0.05) effect in all cases apart from the flavour. CONCLUSION: The overall optimum regions were established at 28 h of germination time, 55 °C drying temperature and 5.0% moisture content for the malting conditions while for the extract production, a roasting temperature of 210 °C, extraction temperature of 70 °C and extraction duration of 20 min were established. Copyright © 2010 Society of Chemical Industry     

秘鲁鱿鱼烤制过程中的水分及质构变化

鱿鱼丝是现代人喜爱的休闲食品,烤制是鱿鱼丝加工中的关键工序,对鱿鱼的品质有重要的影响。本文主要研究了烤制过程中秘鲁鱿鱼的水分、质地、色泽的变化。结果表明,随着烤制时间的延长,秘鲁鱿鱼的水分含量和水分活度降低,损失的主要为中间水和结合水;烤制过程中鱿鱼肉的硬度、咀嚼性、粘着性均有很大程度的提高,弹性下降。      

Determination of optimum processing conditions for hot‐air roasting of hulled sesame seeds using response surface methodology

Sesame paste (tahin) is produced by milling hulled, roasted, sesame seeds. In this study, a hot‐air roasting process for the production of sesame paste was optimised by response surface methodology (RSM) over a range of air temperatures (120–180 °C) for various times (30–60 min). The colour parameters (L, a and b values), browning index (BI), hardness, fracturability and moisture content of the seeds were used as response parameters to develop predictive models and optimise the roasting process. Increases in roasting temperature and time caused increases in the a and b values and in the BI. The hardness and fracturability of seeds also decreased with increasing roasting temperature and time. The quadratic and linear models developed by RSM adequately described the changes in the colour values and textural parameters, respectively. The result of RSM analysis showed that all colour parameters and textural parameters should be used to monitor the roasting of sesame seeds in a hot‐air roaster. To obtain the desired colour and texture, the optimum roasting range for production of sesame paste was determined as 155–170 °C for 40–60 min. Copyright © 2006 Society of Chemical Industry     

Investigation of Efficient Conditions for Oxidative Roasting of Chromite Ore to Produce Potassium Chromate with KOH Additive

A method of producing potassium Chromate directly from chromite ore and KOH was investigated. The chromium recovery was >90% after roasting at 800°C for 3 hours. The KOH‐to‐ore weight ratio was 1.2:1 and the ore‐to‐recycling residue weight ratio was 1:1. Production from the roasting process was easy to leach and about 100% of Chromate could be recovered through a treatment at 30°C for 30~40min with a water/solid ratio of 5:1. The obtained Chromate solution was purified by addition of conventional compounds.