表面活性剂对HCl-FeCl3溶液中锌精矿在浆萃取浸出率的影响

The effects of surfactant on the solvent extraction in leaching sphalerite were investigated. It is found that sodium dodecyl sulfonate is the effective surfactant in improving the zinc recovery from sphalerite in the aqueous FeCl3-HCl-tetrachloroethylene system. Through the measurements of surface tension and viscosity of the sphalerite slurry modified with different surfactants, it is concluded that sodium dodecyl sulfonate in the concentration range of 0.05 to 0.2g L-1 can improve the viscosity of sphalerite slurry in the water, decrease the surface tension of leaching solution, prevent the aggregation of ore particles, and give very high zinc extraction .     

采用高性能搅拌设施生产适应市场的水泥

在欧洲和世界其它地区，CEMⅠ水泥(渡特兰水泥)日益为CEMⅡ水泥(有几个主要组份的渡特兰水泥)和CEMⅢ水泥(高炉矿渣水泥)所替代。为了满足生产具有特定粒径分布的高质量水泥的要求，现广为采用的不同水泥组分的混合粉磨工艺已经被单独粉磨然后再在高性能均化设施中进行均化的工艺所代替。依据情况不同，可以采用连续或间歇式搅拌机。文章描述了不同工艺技术．并介绍了最近的几个实例：     

炼焦中煤深度降灰的研究

分析了中国炼焦煤的储量及利用情况，从利用中国优质煤炭资源的角度出发，以范各庄选煤厂1．40—1．60密度级中煤为实验煤样，以氯化锌为重液，采用浮沉方法将中煤按密度分级，各密度级煤样经磨细后，采用了絮团——浮选工艺，回收各密度中的低灰精煤；探讨从范各庄选煤厂中煤中分选出优质低灰精煤的条件。经过分级及分选后，在相同的分选密度的情况下，总精煤灰分可以降到8．14％以下。     

Effects of soil solution on the dynamics of N2O emissions: a review

In this review, which consists of two parts, major interactions between nitrous oxide (N₂>O) and soil solution are described. In the first part, as an introduction, concentrations of dissolved N₂>O in different aqueous systems are summarized. An inventory of data on maximal N₂>O concentrations in soil solution (up to 9984 g N₂>O-N l^–1>) and in soil air (up to 8300 ppm) from literature is presented. The peak N₂>O concentrations represent a N₂>O supersaturation in the soil solution up to 30000 times with respect to ambient air and a soil air N₂>O concentration about 25000 times higher than in the atmosphere. The main physico–chemical parameters (solubility, diffusion) controlling N₂>O distribution between soil solution and soil air are outlined. The influences of cultivation practice, nitrogen turnover, water content and temperature on N₂>O a ccumulation in soil solution and soil air are reviewed. In the second part some models of N₂>O dynamics in soils are discussed with emphasis on N₂>O transport processes. A simple qualitative scheme is developed to categorize the effects of the soil solution on N₂>O dynamics in soils. In this scheme the temporary, intensive N₂>O oversaturation of the soil solution is interpreted as a result of gas diffusion inhibition by water (barrier function of soil solution) resulting in an accumulation of N₂>O. In addition, N₂>O supersaturation is an indication that transitory much N₂>O can be stored in the soil solution (storage function of soil solution). Where the soil solution flows up-, down- or sidewards it can act as a relevant transport medium for dissolved N₂>O (transport function of soil solution). This scheme is applied to examples from the literature.     

P_2O_5影响Na_2O-B_2O_3-SiO_2系玻璃结构与性质的特殊性

本文通过不混溶温度的确定,分相玻璃沥滤速率的测定以及NMR定量分析,研究了P_2O_6对Na_2O-B_2O_3-SiO_2系统玻璃结构和沥滤性质的影响。结果表明,P_2O_5在很大程度上促进钠硼硅分相玻璃的沥滤并非压抑“硼反常”所致,而是由以下三种因素综合作用的结果:(1)P_2O_5促进了钠硼硅玻璃的分相,使连通富硅相骨架尺寸增大;(2)P_2O_5的加入使富硅相骨架间隙中沉积的SiO_2量减少,减小了可溶相扩散阻力;(3)P_2O_5也使可溶相的溶解速率加快。     

Nitrate leaching from loamy soils as affected by crop rotation and nitrogen fertilizer application

Nitrate leaching as affected by cropping system/crop rotation, history of farmyard manure application or fertilizer nitrogen application (0 N, 0.5 N and 1 N) was studied at nine sites on loamy soils during 1986/87, 1987/88 and 1988/89. Soil solution from 80 to 90 cm soil depth was sampled every second week in the period November to May by the use of porous ceramic cups and analysed for NO₃-N and Cl. Climatical conditions were obtained from standard meteorological observations in the region. Drainage from soil profiles was calculated from measured and simulated values of precipitation and actual evapotranspiration, respectively.The results show that type of crop is of the utmost importance for the leaching magnitude of nitrate as 40% of the total variance in nitrate concentrations in the soil solution could be explained by the type of crop.The second factor of importance was the history of farmyard manure (FYM) application, which was able to explain 28% of the total variation in nitrate concentration in the soil solution. Nitrate concentration/leaching from arable land without FYM ever being applied was considerably lower than from arable land which received periodical FYM applications until the early 70's or from arable land which besides periodical FYM applications in the past presently still receives regular applications of FYM. Only about 1% of the total variation in nitrate concentration in the soil solution was explainable by the level of fertilizer nitrogen application.Differences between years explained 14% of the total variation in nitrate concentration in the soil solution due to differences between the years in soil temperatures and water run-off. The run-off during the autumn and winter of 1986/87, 1987/88 and 1988/89 was 95, 275 and 55 mm, respectively. As expected nitrate leaching increased with increasing run off. However, nitrate leaching at the 275 mm run off was considerably lower than expected, which seems explainable by a substantial denitrification. The soil at the sites in question seems thus partly to purify the soil solution for nitrate before it leaves the root zone at the observed high run off conditions.     

Effect of partial replacement of di(2‐ethyl hexyl)phthalate,by a polymeric plasticizer,on the permeability and leaching properties of poly(vinyl chloride)

Acrylonitrile butadiene rubber (NBR) was used as a polymeric plasticizer in poly(vinyl chloride) (PVC) for the partial replacement of di(2‐ethyl hexyl)phthalate (DEHP). The effect of this partial replacement on DEHP leaching from the PVC was evaluated at 10, 25, and 40°C. The study shows that the incorporation of NBR reduces the rate of DEHP leaching, the reduction being prominent at lower temperatures. Gas permeability of the NBR‐modified samples was also evaluated at the above temperatures using oxygen and carbon dioxide. A reduction in gas permeability is observed in NBR‐modified samples compared to the PVC plasticized with DEHP alone particularly in the case of carbon dioxide. Water vapor transmission rates of the NBR‐modified samples are higher than that of the control sample. The NBR‐modified PVC sample was found to be noncytotoxic in the in vitro cytotoxic evaluation both by direct contact and test on extract methods. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4720–4727, 2006     

世界碳酸钙工业发展近况

世界碳酸钙工业发展迅速，产能不断增加，首先介绍了近几年来重质研磨碳酸钙（GCC）产业的发展概况，重点介绍了中国、日本、马来西亚、韩国、泰国的GCC产业及国际著名GCC生产公司在中国的经营情况。其次介绍了世界轻质沉淀碳酸钙（PCC）的市场概况及国外大型PCC生产公司的基本情况。最后，重点介绍了中国大陆地区的碳酸钙生产与市场情况，并通过分析近几年中国碳酸钙产品的进出口数量及价格情况指出，开发适合碳酸钙用户需求的新产品、新技术，参与国际竞争是今后中国碳酸钙生产企业的发展方向。     

Bauxite residue (red mud) increases phosphorus retention in sandy soil catchments in Western Australia

The Peel-Harvey estuary on the Swan Coastal Plain, Western Australia has become eutrophic partly because of the leaching of fertiliser phosphorus from sandy soils. The acid, coarse textured sandy soils are predominantly quartz, have a low iron and aluminium content and do not retain phosphorus. Red mud, derived from bauxite, is a by-product of the alumina industry and has the ability to retain phosphorus. Retention of phosphorus is enhanced when the red mud is neutralised with gypsum. Red mud has been suggested as a soil amendment to reduce phosphorus leaching.To investigate the reduction in the leaching of phosphorus from soils amended with red mud, weirs were constructed at the outlets from a pair of catchments to quantify the amount of phosphorus in the streamflow. Both catchments were deep grey Bassendean sand. One of the catchments was treated with 80 t/ha of red mud which had been neutralised with waste gypsum from the phosphate industry. The red mud was applied to the soil surface using conventional fertiliser spreading equipment. The other catchment was untreated.The red mud reduced phosphorus loss by 70% from 13.8 kg/ha on the untreated catchment, to 4.2 kg/ha on the treated catchment. Both catchments were treated with 20.4 kg/ha of phosphorus as superphosphate. The catchment treated with red mud also received a further 41.5 kg/ha of phosphorus from the phosphogypsum that was used to neutralise the red mud.Our results show that red mud reduces phosphorus leaching and is potentially a nutrient management option in sandy soils. Red mud has the potential to reduce the impact of agriculture on the estuarine environment and has implications for the continued expansion and intensification of agriculture in the Peel-Harvey catchment.     

富锰渣制备硫酸锰过程中除杂方法新探

研究了以富锰渣为原料,经硫酸浸出制备硫酸锰的工艺过程中除杂方法。分别探讨了以MnO2、H2O2、空气为氧化剂,以NH3.H2O、Ca(OH)2、富锰渣等为中和除杂剂,控制pH在5~6,中和除杂温度为50~60℃,保温时间1~1.5 h情况下,采用不同的除杂剂及除杂条件,取得了不同的除杂效果。