无钙焙烧渣作为焙烧填料的贮存期研究

研究了焙烧填料贮存期对铬铁矿无钙焙烧过程的影响。结果表明,无钙焙烧浸出渣经分选后粗渣作为氧化焙烧填料时,填料的焙烧活性及填料性能随贮存期的延长而提高。在相同配料及焙烧条件下,随着填料贮存期的延长,氧化焙烧熟料中游离碱含量降低、水溶铬含量升高,回转窑的稳定运行时间增长。结合无钙焙烧生产铬盐的工业实践,填料的贮存风化期以6~8个月为宜。     

Textural,Rheological and Sensory Properties and Oxidative Stability of Nut Spreads—A Review

Tree nuts are rich in macro and micronutrients, phytochemicals, tocopherols and phenolic compounds. The development of nut spreads would potentially increase the food uses of nuts and introduce consumers with a healthier, non-animal breakfast snack food. Nut spreads are spreadable products made from nuts that are ground into paste. Roasting and milling (particle size reduction) are two important stages for the production of nut spreads that affected the textural, rheological characteristic and overall quality of the nut spread. Textural, color, and flavor properties of nut spreads play a major role in consumer appeal, buying decisions and eventual consumption. Stability of nut spreads is influenced by its particle size. Proper combination of ingredients (nut paste, sweetener, vegetable oil and protein sources) is also required to ensure a stable nut spread product is produced. Most of the nut spreads behaved like a non-Newtonian pseudo-plastic fluid under yield stress which help the producers how to start pumping and stirring of the nut spreads. Similar to other high oil content products, nut spreads are susceptible to autoxidation. Their oxidation can be controlled by application of antioxidants, using processing techniques that minimize tocopherol and other natural antioxidant losses.     

The Effect of Local Cooking Methods on Polycyclic Aromatic Hydrocarbons (PAHs) Contents in Beef,Goat Meat,and Pork as Potential Sources of Human Exposure in Kisumu City,Kenya

Roasted meat is known to be a major source of human exposure to PAHs. The contribution of direct-heat charcoal-roasted, electric- oven grilled, and shallow-pan fried meat to human exposure in Kisumu City was not known although the three modes of cooking meat are very prevalent. This study analyzed the concentrations of the PAHs in raw beef, goat meat, and pork, investigated the effect of direct-heat charcoal roasting, electric-oven grilling, and shallow-pan frying on these concentrations, and compared their concentration levels with international standards for foods in order to assess the potential risks to consumers. Samples were taken from three popular meat-roasting hotels within Kisumu City, Kenya. Extraction of PAHs was done using liquid-liquid partition after saponification with alcoholic potassium hydroxide followed by clean-up on a silica gel column and final analysis by gas chromatography-mass spectrometry (GC-MS). Roasting and shallow-pan frying introduced new PAHs and significantly (P ≤ 0.05) increased the concentrations of those existing in raw meat. Direct-heat charcoal roast beef had 5 new PAHs and a total mean PAH content of 17.88 μg/kg, compared with a mean of 1.39 μg/kg for raw beef, with the potent dibenz(a,h)anthracene also being detected. Direct-heat charcoal roasted goat meat had three new PAHs and a total mean PAH content of 4.77 μg/kg, compared with a mean of 2.13 μg/kg in raw meat, with the potent benzo(a)pyrene concentration being 8.84% of the total mean PAH. Fried pork had 7 new PAHs and a total mean PAH content of 3.47 μg/kg, compared with a mean total of 0.17 μg/kg, detected in the raw meat. Roast beef had the highest individual PAH concentration (5.03 μg/kg) and highest total PAHs concentration (17.88 μg/kg), both being higher than acceptable EU limits. The PAHs from local raw and cooked meat were characterized and quantified for the first time in Kisumu City and the study therefore provided the needed baseline data on PAHs in raw and cooked meat.     

小型高砷硫化金矿制酸系统工艺参数的确定

高砷硫化金矿采用一段沸腾焙烧,焙砂提金、烟气制酸.在焙烧温度900～950℃、焙砂颜色控制为深褐色的条件下,高砷硫化金矿脱硫、砷效果较好,焙砂金浸出率达到90%.副产冶炼烟气采用一转一吸工艺制酸,总硫利用率可达92%.     

新型分子筛焙烧炉的结构及其计算机控制系统

从机械与控制的双重角度介绍了一种新型立式焙烧炉的结构及其控制的方法。焙烧炉采用了筒体置于能自动开合的炉膛内的新型结构,在机械设计方面采取了一些有效的措施,同时采用组合逻辑控制方法将复杂的控制过程转化为简单控制,实现了焙烧炉的自动化操作。实际运行结果表明,SSY和PTY 2种分子筛的产品收率均由86%提高到96%,产品合格率由94%提高到99%。     

利用正交试验确定钒渣焙烧的最佳工艺条件

介绍了钒分厂利用正交试验法进行试验方案的设计及试验结果的直观分析，确定出钒渣烙烧的最佳工艺条件是：钒渣粒径小于0．12mm，烙烧气中氧气体积分数大于10％，焙烧温度850℃，烙烧时间60min，碱比(碱与钒渣质量比)16％，盐比(盐与钒渣质量比)5％，从而改变了以往在生产和转渣时组织生产的被动局面，为公司创造了可观的经济与社会效益。     

The content of tocopherols and oxidative quality of oils prepared from sunflower (Helianthus annuus L.) seeds roasted in a microwave oven

Sunflower seeds ((Helianthus annuus were roasted for 6, 12, 20 or 30 min at a frequency of 2450 MHz using a domestic microwave oven. After the kernels were separated from the sunflower seeds, the quality characteristics and the compositions of the oils were investigated in relation to their tocopherol distributions, and they were further evaluated as compared with an unroasted oil sample. Only minor increases (p < 0.05) in chemical and physical changes of the oils, such as the carbonyl value, the p‐anisidine value and the color development, occurred at a prolonged roasting period. Significant decrease (p < 0.05) was observed in the amounts of phospholipids in the oils after microwave roasting. Nevertheless, compared to the original level, more than 92 wt‐% tocopherols still remained after 30 min of roasting. With a few exceptions, these results indicate that the exposure of sunflower seeds to microwaves for 12 min caused no significant (p < 0.05) loss or change in the content of tocopherols and polyunsaturated fatty acids in the kernels.     

化学工业固体废物毒性分析研究

介绍了对硫酸烧渣和磷石膏两种固体废物进行急性毒性和浸出毒性鉴别试验的过程与结果,并对磷石膏由危险废物转变为非危险废物的原因进行了探讨,为硫酸烧渣和磷石膏的处置和利用提供了依据.     

微山稀土精矿经固氟后采用氯化铵法回收稀土

微山稀土精矿经固氟后，采用氯化铵法回收稀土. 通过单因素条件实验确定了矿物固氟和氯化焙烧的较宜条件：固氟温度为550℃，固氟剂用量与精矿质量比为1:20，固氟焙烧时间50 min; 氯化剂用量与精矿质量比为1.2:1，氯化焙烧温度480℃，氯化时间60 min. 在较宜条件下，稀土的浸出回收率在87.8%以上. 利用X射线衍射探讨了固氟过程中可能发生的反应.     

粉煤灰与硫酸氢铵焙烧反应动力学

提出了NH4HSO4法焙烧粉煤灰提取Al2O3的新方法,考察了焙烧温度、粉煤灰中Al2O3与NH4HSO4摩尔比对粉煤灰中Al反应率的影响,研究了粉煤灰与NH4HSO4焙烧反应动力学. 结果表明,粉煤灰与NH4HSO4焙烧反应受固体产物层扩散控制,300, 350, 400℃下的反应速率常数分别为1.25′10-3, 1.56′10-3, 1.89′10-3 min-1,反应活化能为17.19 kJ/mol,反应动力学方程为1-2/3a-(1-a)2/3=0.0422exp[-17190/(RT)]t,最佳工艺条件为：焙烧温度400℃,Al2O3与NH4HSO4摩尔比1:8,焙烧时间60 min;该条件下Al反应率达90%以上,主要产物为NH4Al(SO4)2和NH4Fe(SO4)2.