Evaluation of levels and methods of zinc application to rice in sodic soils

Field experiments were conducted in zinc-deficient sodic soil to study the effect of levels and methods of zinc fertilization on yield, concentration and uptake of zinc by rice. Zinc was incorporated in the soil at the rate of 0, 5.6, 11.2 and 22.4 kg Zn per ha as zinc sulfate; sprayed on the plants at 1% and 2% zinc sulfate solution; and roots of rice seedlings were dipped in 2% and 4% ZnO suspensions in water. Grain yield, zinc content and its uptake increased in all the experiments up to 22.4 kg Zn per ha. Soil applied zinc was significantly correlated with yield of rice (r = 0.80^**) and zinc uptake (r = 0.89^**). Zinc content in 45-day old plants gave a significantly higher correlation with grain yield (r = 0.84^**) than the zinc content of rice straw and grain at maturity. Roots of rice seedlings dipped in 2% or 4% zinc oxide suspension in water were not only comparable with soil application of Zn at 5.6 and 11.2 kg Zn per ha, but also proved to be more economical for sodic soils showing moderate zinc deficiency.     

动力波ZnO脱硫技术在铅锌冶炼尾气脱硫中的应用

介绍了动力波氧化锌脱硫技术在铅锌冶炼行业制酸尾气脱硫中的应用情况.该脱硫装置采用铅冶炼烟化炉产生的氧化锌浆液作为脱硫剂,使排放气体SO2质量浓度从2 g/m^3降至200 mg/m^3以内,确保制酸尾气达标排放.脱硫产生的硫酸锌用作炼锌原料不产生二次污染.针对运行中存在的问题,技术人员通过不断技术改造,优化工艺参数,基本予以解决,确保了装置平稳运行.     

Direct and residual effect of fertilizer zinc application on the yield and chemical composition of rice-wheat crops in an alkali soil

A field experiment was conducted on an alkali soil to evaluate the direct and the residual effect of six levels of zinc i.e. 0, 2.25, 4.5, 9.0, 18.0 and 27.0 kg Zn ha^–1 added either once to the first crop only or continuously to each crop on the growth, yield and chemical composition of plants grown in a rice-wheat cropping sequence. The soils were amended with gypsum applied at the uniform rate of 14 t ha^–1. Zinc was supplied as zinc sulphate. Application of zinc at the rate of 2.25 kg ha^–1 to both rice and wheat crops or an annual application of 4.5 kg Zn ha^–1 only to rice was found optimum for rice-wheat sequence. Higher zinc applications increased the availability of zinc in the soil and its content in the plants but did not increase crop yield. DTPA extractable zinc build up was more for zinc applied at the rate of 2.25 kg ha^–1 to each crop compared to a single zinc application of equivalent amount. Results of these studies have shown that continuous Zn application up to 27 kg Zn ha^–1 to each crop did not induce nutrient imbalances and had no adverse effect on crop yield.     

Relative efficiency of zinc oxide and zinc sulphate-enriched urea for spring wheat

Field experiments conducted at the Indian Agricultural Research Institute, New Delhi during 2005–2007 showed that the application of small amounts of zinc (Zn) in the form 0.5–2.0% of Zn-enriched urea significantly increased yield attributes, grain and straw yield, Zn concentrations in the grain and straw and Zn uptake by spring wheat. The agronomic and crop recovery efficiency of applied Zn decreased as the level of Zn-enrichment was increased from 0.5 to 2%. Zinc sulphate (ZnSO₄) and zinc oxide (ZnO) were equally effective in increasing the grain yield of wheat. Based on these results, we recommend the application of a 0.5–1.0% Zn enrichment of urea with ZnSO₄ or a 1.0% Zn-enrichment with ZnO.     

硫酸锌溶液脱除钙镁试验及生产应用

某硫酸锌生产厂,由于原料氧化锌矿中钙镁含量较高,用硫酸浸出后的硫酸锌溶液中钙镁含量也较高,导致生产的硫酸锌产品钙镁含量偏高,主含量偏低,影响了硫酸锌产品质量。对氢氟酸沉淀法脱除硫酸锌溶液中的钙镁离子进行了试验研究及生产应用。用氢氟酸作为沉淀剂,在较低温度和较高pH条件下可有效脱除硫酸锌溶液中的钙镁离子,并能控制氟在溶液中的累积,使制得的硫酸锌产品质量得以提高。     

大比表面积活性氧化锌在轮胎肩垫胶中的应用

研究了大比表面积活性氧化锌在轮胎肩垫胶中的应用效果。试验结果表明 ,用 5份大比表面积活性氧化锌替代 8份普通氧化锌 ,胶料的门尼粘度略有下降 ,焦烧时间和t10 稍有延长 ,t90 缩短 ;硫化胶的邵尔A型硬度、拉伸强度、30 0 %定伸应力和撕裂强度均有所提高 ,而扯断伸长率和固特里奇生热有所降低 ;采用试验配方生产的轮胎成品性能明显提高 ,且配方成本下降     

Effect of different sources of iron and sulphur on leaf chlorosis,nutrient uptake and yield of groundnut

The pot experiment conducted in calcareous soil of Saurashtra, India showed that application of lime (20% CaCO₃) and excess water (irrigation at –0.3 bar) to the soil enhanced chlorosis in groundnut leaves caused by induced deficiencies of iron, sulphur and zinc, which was recovered by applying agricultural grade chemicals containing iron, sulphur and zinc. This chlorosis caused 29.8 and 19.1% reduction in pod yield of groundnut due to lime and excess water, respectively in the untreated control pot and 17.1 and 9.6%, respectively in the pot treated with different chemicals.Application of iron sulphate, zinc sulphate, iron pyrite, gypsum, phospho-gypsum, elemental sulphur, wettable sulphur and Fe-EDTA decreased chlorosis and increased chlorophyll and carotenoid contents of leaves, uptake of Fe, S and Zn and pod yield of groundnut significantly. The foliar spray of 0.5% aqueous solution of iron sulphate, zinc sulphate and Fe-EDTA at 20, 35, 50 and 65 days after emergence (DAE) was more effective than their soil applications. The Fe-EDTA corrected only iron chlorosis, and gypsum, phosphogypsum and elemental sulphur only sulphur chlorosis. However, iron sulphate and iron pyrite corrected iron and sulphur and zinc sulphate corrected zinc and sulphur chlorosis. Among the soil amendments, application of iron sulphate and iron pyrite showed better responses to groundnut and showed higher Fe and S uptake than other treatments. The responses of gypsum, phosphogypsum and elemental sulphur were at par. The correlation study showed that pod yield of groundnut was negatively correlated with chlorosis and positively correlated with the chlorophyll and carotenoid contents in groundnut leaves.     

氧化锌法烟气脱硫技术的工业化应用

介绍了氧化锌法脱硫原理及工艺流程、设备配置情况.河南豫光锌业挥发窑尾气氧化锌法脱硫系统采川两级湍冲洗涤器洗涤工艺,以确保外排烟气p(SO2)≤250mg/m(3),设计采用控制管道流速、设置管道回路和支管等措施以解决管道堵塞问题,同时探讨了脱硫副产物硫酸锌溶液几种资源化利用技术方案.负荷调试测试表明,在烟气量8.0×1...     

利用次氧化锌粉制备活性氧化锌工艺研究

研究了利用硫酸浸出次氧化锌粉制备活性氧化锌的工艺。讨论了浸出过程中液固比、硫酸浓度对浸出率的影响;采用加氧化锌粉末、加热、调节pH和锌粉置换的方法提纯硫酸锌溶液;采用碳酸氢铵作为沉淀剂制备前驱体碱式碳酸锌。通过实验,确定了利用次氧化锌粉制备活性氧化锌的工艺参数。采用扫描电镜和X射线衍射对活性氧化锌进行了表征,结果表明：活性氧化锌的粒度分布均匀,形貌为球形立方,产品纯度高,氧化锌质量分数为99.48%。     

负载型纳米氧化锌在橡胶中的应用研究

氧化锌作为一种良好的硫化活性剂,在橡胶生产中已被广泛使用,但锌基材料对人体健康和生态环境存在不良影响,因此如何在橡胶配方中减少锌的含量已经成为目前橡胶行业重要的研究课题。纳米氧化锌因为具有纳米粒子特有的优势,因此在使用中可以达到锌减量的目的,但纳米粒子容易团聚,限制了纳米效应的发挥;广东韶关凯鸿纳米材料有限公司开发了一种负载型的纳米氧化锌,将纳米氧化锌粒子包覆在载体上的新型制品,提高反应活性,减少团聚,可以使纳米氧化锌充分发挥纳米粒子的优势,同时有效的减少锌在橡胶制品中的残余量。本工作分别采用普通氧化锌、纳米氧化锌、负载型纳米氧化锌(C型、A型、S型)作为活化剂,其中负载型纳米氧化锌依据载体不同进行分类,C型的载体为碳酸钙,A型的载体为氧化铝,S型载体为二氧化硅。通过各项性能测试实验,重点研究负载型纳米氧化锌对橡胶综合性能的影响。实验结果表明,相对于普通氧化锌,负载型纳米氧化锌作为活化剂,可以在锌的使用量明显下降的情况下,制备出达到甚至优于普通氧化锌制品性能的橡胶复合材料。其中,3份用量的A型负载型纳米氧化锌的活化作用最优。     

用锌渣制备高纯氧化锌

介绍了利用锌渣为原料生产高纯氧化锌的方法。采用黄铁矾法除去大部分铁，通过控制ｐＨ值进一步除铁，用锌粉或锌屑还原除去重金属，用氨水为沉淀剂，最终可使氧化锌的含量达９９．８６％以上。     

Determination of critical level of zinc in non-calcareous soils for predicting response of wheat to applied zinc

Studies were conducted in ten non-calcareous arid brown soils (India) to determine the critical level of soil Zn for predicting response of wheat to zinc fertilization. The per cent mean response at 5 mg kg^–1 added Zn varied from 1.3 to 51.4 with a mean value of 17.5 per cent over control in terms of grain yield (g pot^–1). Further, Zn application resulted in significant increase in Zn concentration in various plant parts in all the soils irrespective of the initial Zn status. The critical level of Zn in soil and plant below which response to applied Zn may be expected was found to be 1.75 mg kg^–1 for 0.1 N HC1 extractable soil Zn and 1.7 mg kg^–1 for plant tissue Zn.     

锌灰制备碱式碳酸锌和超细氧化锌及表征

室温下采用氨浸出锌灰制得碱式碳酸锌,再经煅烧制得超细氧化锌。研究了在合成碱式碳酸锌过程中表面活性剂对碱式碳酸锌和氧化锌颗粒尺寸与形貌的影响。结果表明,聚乙二醇（PEG20000）和聚乙烯吡咯烷酮（PVP-K30）这两种表面活性剂对颗粒的分散效果最好,制得的碱式碳酸锌颗粒为无定形片状且分散均匀,平均粒径为1 μm,煅烧后的氧化锌颗粒为六方晶系纤锌矿结构,粒径约为0.7 μm。添加PVP-K30比添加PEG20000的碱式碳酸锌热分解温度高。添加PEG和PVP的碱式碳酸锌反应活化能分别为139.9 kJ/mol和146.8 kJ/mol。     

水解沉淀法制备超细碱式碳酸锌的试验研究

以碳酸氢铵和氨水浸出锌灰,然后经除杂净化得到高纯锌氨溶液,以高纯锌氨溶液为原料,采用加热水解沉淀法合成超细碱式碳酸锌,碱式碳酸锌经煅烧得到超细氧化锌。研究了加热水解沉淀工艺条件对碱式碳酸锌的粒径分布的影响。结果表明,最佳工艺条件为：搅拌速度为300 r/min、蒸氨温度为90 ℃、锌氨溶液中锌质量浓度为75 g/L、负压为-2 kPa。最佳工艺条件下得到的碱式碳酸锌的D50为0.77 μm,颗粒近似球形;煅烧后的氧化锌为六方晶系纤锌矿结构,D50为0.69 μm。     

硫酸铵-氨水溶样测定氧化锌含量

研究采用硫酸铵-氨水溶解氧化锌试样,EDTA滴定法测定氧化锌含量.结果表明,用200 g·L<'-1>硫酸铵溶液10 mL,5 mL氨水溶解分析试样,搅拌5 min后试样中氧化锌溶解完全,金属锌、氧化铁等杂质不溶,氧化锌的测定不受这些杂质的干扰,测定结果与传统溶样方法的测定结果相吻合,相对标准偏差小于0.1%.     

纳米ZnO的光催化性能及软化学合成研究进展

纳米Zn0是一种性能优异的新型功能材料，其应用前景非常广阔。本文仅对纳米ZnO的光催化性能及软化学合成的研究进展予以综述。     

纳米氧化锌的制备与应用

纳米氧化锌作为一种功能材料，有着许多优异的性能和广泛的应用价值。对纳米氧化锌在国内外的研究现状、制备技术(固相法、液相法和气相法)及其应用状况进行了较为系统的评述，并提出了进一步研究的方向，对纳米氧化锌的形成机理及微观结构进行探讨，寻求行之有效的制备高纯、均匀纳米氧化锌的方法，以及制备各种性能的氧化锌粉体。     

氧化锌精制的生产实践

以氧化锌为原料，利用精制炉生产特种陶瓷用精制氧化锌。介绍了主要的工艺流程、设备投资、主要原材料和技术经济指标及产品质量。工艺简单、无污染、投资少。产品质量经陶瓷厂家大批量使用，氧化锌化学指标和物理规格符合特种陶瓷需要。     

高性能钼酸锌/碱式钼酸锌微粉合成研究*

探讨了合成高性能钼酸锌/碱式钼酸锌的新工艺。利用X射线衍射（XRD）、扫描电镜（SEM）、电感耦合等离子体原子发射光谱对钼酸锌/碱式钼酸锌的结构、形貌和元素进行表征和分析。合成工艺及条件：三氧化钼和氧化锌在乙醇溶液中在30 ℃反应30 min,过滤所得滤饼在110 ℃干燥,之后采用程序控温合成钼酸锌/碱式钼酸锌。该方法具有大幅度缩短合成时间和节约电能的优点,钼酸锌/碱式钼酸锌的收率可以达到94%以上。     

纳米氧化锌在工程胎配方中的研究与应用

介绍了纳米氧化锌在工程胎胎面上层胶及缓冲层胶配方中的研究与应用,分别在工程胎胎面上层胶及缓冲层胶使用纳米氧化锌按 60%、70%、80%的比例代替普通氧化锌进行对比试验,实验结果表明,使用纳米氧化锌按70%比例代替普通氧化锌,胶料的硫化特性整体后移延迟,胶料比重下降,拉伸强度略有提高,定伸应力提高明显,胎面磨耗显著下降,生热性能降低,撕裂性能和H抽出性能有所提高,老化性能有所改善,成品性能优于正常配方;并且配方成本有一定的降低。