真空热还原制锂工艺的技术经济分析

系统介绍了以碳酸锂为原料 ,加入石灰或铝氧土后 ,经焙烧、硅铁或铝粉真空热还原制取金属锂的工艺。本法与氯化锂熔体电解制取锂的工艺相比 ,具有产品成本低、纯度高、环境状况好的优点。     

单─银精矿提取银的技术

某单─银矿经浮选所得精矿（％）：Ａｇｌ～２，Ｃｕ≈１，Ｐｂ４～７，ＣａＯ＋ＭｇＯ３０～３５，Ｓ４～７，Ｃ８～９。研究了氰化、硫脲、氨浸等方案对该精矿浸出效果，并从浸出指标等因素进行比较，认为焙烧─预浸─氨浸方案较好，银浸出率＞９７％，铜浸出率９５％。     

用针铁矿法从锌焙烧烟尘的热酸浸出液中除铁

研究了从锌焙烧烟尘常压热酸浸出液中沉淀针铁矿的过程。试验结果表明,反应时间和空气流量对除铁率的影响不显著,而反应温度和溶液终点pH是除铁过程的主要影响因素。在终点pH3.0、反应温度333 K、反应时间2 h、空气流量0.2 m3/min的条件下,除铁率超过99.5%,溶液中铁浓度可由40g/L降至0.1 g/L以下。     

Antioxidant Properties of Cocoa Beans (Theobroma cacao L.): Influence of Cultivar and Roasting Conditions

Effects of various roasting conditions on antioxidant properties of five Theobroma cacao L. varieties were investigated. The cocoa beans were roasted at four different temperatures (110–150°C) and three different air humidities (0.3–5.0%). The raw cocoa beans were characterized by high antioxidant activities. The antioxidant properties of the roasted cocoa beans varied markedly among the analyzed cultivars and geographical regions and were affected by roasting conditions. Generally, cocoa beans of the cv. Forastero from Brazil exhibited higher total phenolic content, free radical scavenging activity, and metal chelating ability than samples of the other analyzed cocoa varieties. Roasting at 110°C caused negligible changes in total phenolics content and antioxidant activity of cocoa beans, while almost all samples tended to have lower antioxidant potential when roasting temperature increased. The air humidity used in roasting did not affect the total phenolics content and antioxidant activity for lowest roasting temperature (110°C). Moreover, the obtained results revealed that thermal processing at the higher temperatures and elevated air humidity resulted in the higher antioxidant capacities. It was also found that the ferrous ion chelating activity of cocoa beans increased with the roasting temperature (in the range from 110 to 150°C), with the exception of cv. Trinitario from Papua New Guinea. The data showed that roasting at lower temperatures with humid air are more favorable in terms of preserving the bioactivity of roasted cocoa beans.     

Thermodynamic analysis of the carbothermic reduction roasting of a nickeliferous limonitic laterite ore

As the sulfide ore deposits become less economically viable as a source of nickel, increasing attention is being paid to the nickeliferous laterite ores. However, in contrast to the sulfide ores, these oxide ores cannot be as easily concentrated by current technologies. Consequently, considerable research effort is being directed at developing new techniques for beneficiating the nickeliferous laterites. The pyrometallurgical production of a high-grade ferronickel alloy using a low cost carbonaceous reductant at relatively low temperatures is particularly attractive. In the current research, a thermodynamic model has been developed to aid in the understanding of the carbothermic reduction roasting process as a potential upgrading method for the nickeliferous limonitic laterite ores. The effects of process parameters such as temperature and reductant to ore ratio on the grade of the ferronickel alloy produced and the nickel recovery in the alloy have been studied. The thermodynamic predictions are shown to be in general agreement with the experimental results currently available in the literature.     

Formation of Benzo(a)pyrene in Sesame Seeds During the Roasting Process for Production of Sesame Seed Oil

The main aim of this research was to enhance the understanding of the formation mechanisms of benzo(a)pyrene (BaP) during roasting of sesame seeds (SS). BaP levels in hot‐ and cold‐pressed sesame seed oil (SSO) were evaluated to correlate oil technology and BaP formation. Extracted principal components from SS were roasted either singly or in mixtures at 230 °C for 30 min. BaP was measured by HPLC with fluorescence detection. The results showed that BaP levels in hot‐pressed SSO were significantly higher than those in cold‐pressed SSO (p < 0.05), BaP formation mostly occurred during SS roasting and increased with roasting temperature (between 80 and 280 °C) and time (from 10 to 50 min). Furthermore, the BaP level in the roasted hulled SS (3.64 μg/kg) was higher than it was in roasted whole SS (1.63 μg/kg). The maximum BaP level observed (5.03 μg/kg) was detected in a roasted mixture of SS protein and SSO. The addition of sesame protein to protein‐free SSO promoted the formation of BaP, which suggests that the pyrolysis products of protein and triacylglycerols are probably important precursors in BaP formation.     

碘化浸金试验研究

碘化浸金是一种新的非氰化浸金方法。文章详细介绍了不适合浮选处理的含碳原生金矿焙烧试验和碘化浸出时各影响因素试验。分析了各种实验现象，通过试验得出了合理的焙烧温度为650℃、碘化浸出率可提高15％左右，浸出速度快等结论。     

石煤提钒的工艺评价

钒是一种重要的战略物资，具有广泛的用途。石煤是我国独特的一种矶矿资源，储量极为丰富。从石煤中提取V2O5是获得钒的重要途径。文中旨在对传统提钒工艺流程进行评价的基础上，总结了石煤提钒中的一些新工艺，并对石煤提钒工艺前景进行了展望。     

菱锌矿湿法炼锌试验研究

以某地菱锌矿为原料,采用焙烧—浸出—净化—电解—熔铸的工艺流程进行试验研究,获得了牌号为Zn99. 95的锌锭产品,锌的冶炼总收率达95%以上。本工艺流程技术可行,经济上较为合理,所需生产设备简单,易于实现工业化生产。