磷矿的电选试验研究

清水沟中低品位磷矿性质复杂，嵌布粒度细，磨至-0．174mm 92．8％，通过振动—气流联合作用摩擦荷电，采用悬浮电选机经-粗-精-扫电选。可由含P2O5为24．47％的原矿获得含P2O5为30．23％。回收率为83．26％，杂质含量合格的磷精矿。     

含铁矿物吸附剂除磷机理研究及中试应用

研究了含铁矿物吸附剂吸附含磷废水的各项性能,通过静态试验得出此吸附剂的最佳吸附条件,并以此为依据进行了动态小试试验和中试试验。结果表明,含铁矿物吸附剂的吸附平衡时间为45h,吸附等温线较符合Freundlich方程,pH约为5时吸附量达到最大,除铁离子和铝离子外,水体中无机阴离子和阳离子对磷酸盐的吸附影响不大。用1mol/L的NaOH溶液对饱和吸附剂解吸再生,解吸率达到90%以上。在合适的填充体积和进水流速下,含铁矿物吸附剂连续吸附除磷可以达到良好的效果,中试试验装置连续运行了约105d,出水TP达到了《地表水环境质量标准》(GB3838—2002)(Ⅲ类湖、库)要求。     

低铁耗条件下转炉高碳低磷工艺实践与应用

对转炉炼钢实现低铁耗和高碳低磷工艺进行了分析，介绍了南钢公司转炉炼钢实践低铁耗条件下高碳低磷工艺的具体应用措施。     

Groundwater-surface water interactions and agricultural nutrient transport in a Great Lakes clay plain system

Nutrient export from agricultural land to surface waters is a significant environmental concern within the Great Lakes Basin (GLB). A field-based watershed-scale study was completed to investigate spatial and temporal variations of phosphorus and nitrate to assess nutrient transport pathways and groundwater-surface water interactions in an agriculturally dominated clay plain system. This was conducted in the 127 km² Upper Parkhill Watershed, near Lake Huron in southwestern Ontario, Canada. Data collection occurred from June 2018 to May 2019 via continuous sensor deployment and discrete sampling of stream water, groundwater, hyporheic zone, and tile drainage water. Samples were analyzed for various nutrient species (total, total dissolved, soluble reactive, and particulate phosphorus, and nitrate-N) to examine the hydrological dynamics of principal transport pathways of agriculturally-derived nutrients. Total phosphorus and nitrate concentrations in stream water ranged from 0.007 to 0.324 mg/L and 0.32 to 13.13 mg NO₃^?-N/L, respectively. Tile drainage water total phosphorous concentrations varied from 0.006 to 0.066 mg/L. Groundwater total dissolved phosphorus concentrations ranged from <0.003 to 0.085 mg/L. Transport of phosphorus through tile drainage was observed to be greater than through groundwater over the study period. No distinct relationship was observed between nutrient concentrations in the hyporheic zone and the vertical hydraulic gradient within this zone in the studied stream reach. Preliminary correlations were discerned between water quality observations and recognized land management practices. Given the elevated stream nutrient concentrations, these results are consequential for the continual improvement of strategies and programs devised to conserve water resources within the GLB.     

三聚氰胺甲醛树脂包覆不同目数红磷的稳定化研究

采用原位聚合方法制备了三聚氰胺甲醛树脂包覆不同目数的红磷。对包覆红磷进行了扫描电镜、X射线光电子能谱(XPS)、吸水性、抗氧化性、pH值及热重分析测试。扫描电镜和XPS结果表明,三聚氰胺甲醛树脂在红磷表面形成了有效包覆。吸水率结果表明,三聚氰胺甲醛树脂包覆后的红磷,其吸水率随着时间增长显著降低,7 d后的吸水率低于0.6%;抗氧化测试表明,其抗氧化能力比未包覆红磷提高27倍以上;热失重结果表明,包覆后起始氧化增重温度提高70℃以上。1000目包覆红磷的稳定性比1500目更优。     

A phosphorus budget of a poultry farm and a dairy farm in the southeastern U.S., and the potential impacts of diet alterations

Current and potential environmental problems associated with P transport from lands receiving high application rates of animal waste are a major concern. Phosphorus management strategies are needed to reduce P loading on land. This study was conducted to compare on-farm P budgets for a modern broiler farm and a dairy farm under traditional diets and management practices. Phosphorus inputs, recycling and outputs were assessed for both farms. A typical broiler and a dairy farmer from North Carolina were interviewed and pertinent information for the study was obtained, in cooperation with extension agents, and other professionals associated with the farms. The annual on-farm P surplus for the broiler farm was 6,380 kg, while that for the dairy farm was 1,141 kg. This corresponds to an annual application of 65 kg P ha^–1 for the broiler farm and 20 kg P ha^–1 for the dairy farm in excess of removal. The potential for reducing P surpluses by the addition of phytase enzymes and/or the use of low phytic acid corn (Zea mays L.) feed in the broiler farm diet was also assessed. Estimates by animal nutritionists indicate that feed supplementation with phytase enzyme can reduce the broiler farm's P surplus by 33%. The use of low phytic acid corn can reduce the surplus by 49% and a combination of the two can reduce the surplus by 58%. In this study, the incorporation of soybean (Glycine max (L.) Merr.) and alfalfa (Medicago sativa) land into the waste utilization plan of the dairy farm decreases the annual P surplus from 20 to 9 kg P ha^–1. The use of new feed technology and expanding waste application to a larger land base can significantly alter the P budgets of broiler and dairy farms and reduce P surpluses, minimizing the risk of environmental problems.     

Transport of phosphorus forms and of nitrate through a clay soil under grass and cereal production

Many nutrients are lost from soil to water viatile drains. However, there are very few reliable studies of such phosphorus(P)losses under Swedish agriculture practices, especially in connection tofertiliser and slurry applications and related to nutrient balances. Tile drainlosses were measured from nine experimental plots in south-west Sweden; fourplots were measured for 7 years and five plots for 2–3 years. Cereals,mainly spring barley (Hordeum vulgare, L.) and oats(Avena sativa, L.), were grown in six plots, while oneplotwas cultivated with grass, timothy (Phleum pratense L.)andmeadow fescue (Festuca pratensis, L.), one with lucerne(Medicago sativa, L.) and meadow fescue (F.pratensis, L.), and the last one was a set-aside withgrass (Lolium perenne, L. and Trifoliumrepens, L.) that was neither fertilised nor used for crop removal.Attention was paid to the forms in which P was transported to water since thishas important ecological implications. Average losses of particulate P (PP)fromthe set-aside land was significantly lower than from the cerealproduction, but the average losses of soluble reactive P (SRP) and dissolvednonreactive P (DUP) were the same. Average loss of PP from the grass ley during 3years (0.09 kg per ha^–1 y^–1) wassignificantly less than the losses from cereal production. Total P loss of 0.3kg per ha^–1 y^–1 was equal to the averagelossfrom the Swedish monitoring network of observation fields. Compared to theaverage nitrate-nitrogen (NO₃-N) leaching, which was 7 kg perha^–1 y^–1 from cereals, the NO₃-Nleaching was very low from the plots with lucerne-grass and set-aside.After applying and directly ploughing in 80 kg ha^–1 ofsuperphosphate for cereal production in November 1998, 0.6–1.8 kgSRP ha^–1 y^–1 was lost through the drain tiles.Surface application of cattle slurry in spring 1999 to the grass ley alsoresulted in a very pronounced increased base level of SRP. This paper documentsthe importance of applying slurry during dry conditions and of placingfertiliser into the soil according to crop requirements in the time perspectiveof one year.     

The combined effect of fertiliser nitrogen and phosphorus on herbage yield and changes in soil nutrients of a grass/clover and grass-only sward

The combined effect of reduced nitrogen (N) and phosphorus (P) application on the production of grass-only and grass/clover swards was studied in a five-year cutting experiment on a marine clay soil, established on newly sown swards. Furthermore, changes in soil N, P and carbon (C) were measured. Treatments included four P (0, 35, 70 and 105 kg P ha^–1 year^–1) and three N levels (0, 190 and 380 N kg ha^–1 year^–1) and two sward types (grass-only and grass/clover). Nitrogen was the main factor determining the yield and quality of the harvested herbage. On the grass-only swards, N application increased the DM yield with 28 or 22 kg DM kg N^–1, at 190 or 380 kg N ha^–1 year^–1, respectively. The average apparent N recovery was 0.78 kg kg^–1. On the grass/clover swards, N application of 190 ha^–1 year^–1 increased grass production at the cost of white clover, which decreased from 41 to 16%. Phosphorus application increased grass yields, but did not increase clover yields. A positive interaction between N and P applications was observed. However, the consequences of this interaction for the optimal N application were only minor, and of little practical relevance. Both the P-AL-value and total soil P showed a positive response to P application and a negative response to N application. Furthermore, the positive effect of P application decreased with increasing N application. The annual changes in P-AL-value and total soil P were closely related to the soil surface surplus, which in turn was determined by the level of N and P application and their interaction. The accumulation of soil N was similar on both sward types, but within the grass-only swards soil N was positively affected by N application. The accumulation of organic C was unaffected by N or P application, but was lower under grass/clover than under grass-only.     

19 500 kVA三相6根电极制磷电炉性能考核总结

针对19500 kVA三相6根电极制磷电炉在试生产中出现的炉气温度高、电极位置高,消耗、成本居高不下等现象,通过性能考核,分析了主要原因是入炉焦炭水分高、粒度过大过细,洗涤收磷系统热量不够,电极布置有过热区,操作纪律执行不严格,仪表监测不准等。综合评价了该制磷电炉生产能力和存在问题,提出只有通过对原料质量、操作指标的严格控制、科学管理、整改和完善存在问题,以期该制磷电炉在最佳和优惠工艺条件下运行。     

Groundnut Yield Response to Single Superphosphate, Calcitic Lime and Gypsum on Acid Granitic Sandy Soil

Phosphorus and calcium are the major nutrients limiting groundnut production. The objectives were to determine (a) optimum application levels of P and Ca, and (b) compare the effectiveness of calcitic lime (40% Ca, 4.5% Mg) and gypsum (22% Ca, 17% S) as sources of Ca for groundnut grown on sandy soils. Field experiments were established in smallholder farming areas using four levels of P (0, 8.5, 17 and 34 kg ha⁻¹) combined factorially with calcitic lime (0, 200, 400 and 800 kg ha⁻¹) to give 16 treatments. Similar levels of P were combined factorially with gypsum (0, 100, 200 and 400 kg ha⁻¹) to give sixteen treatments. Experiments were laid in a randomized complete block design with three replications. Phosphorus had a significant effect on groundnut yield at the majority of the experimental sites. Application of P at 8.5 kg ha⁻¹ gave the optimum groundnut yield response. The optimum application rates for calcitic lime and gypsum were 200 and 100 kg ha⁻¹. Gypsum and calcitic lime were not significantly different as sources of Ca for groundnut. Soil chemical properties were significantly improved following application of P and Ca sources.