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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。 相似文献
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Ceilidh Mackie Jana Levison Andrew Binns Ivan O'Halloran 《Journal of Great Lakes research》2021,47(1):145-159
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. 相似文献
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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. 相似文献
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Transport of phosphorus forms and of nitrate through a clay soil under grass and cereal production 总被引:1,自引:0,他引:1
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. 相似文献
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19 500 kVA三相6根电极制磷电炉性能考核总结 总被引:1,自引:2,他引:1
孙志立 《硫磷设计与粉体工程》2007,(5):23-29
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。 相似文献
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Groundnut Yield Response to Single Superphosphate, Calcitic Lime and Gypsum on Acid Granitic Sandy Soil 总被引:1,自引:0,他引:1
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. 相似文献
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