摘要
【目的】钢渣是缓释硅钙肥原料,钢渣中硅素释放受钢渣自身性能和外界环境条件等因素影响,本文设置了钢渣冷却方式、钢渣粒径、培养介质和培养温度四种因子,研究钢渣中硅素释放规律及其影响因素,为钢渣硅钙肥合理施用提供理论依据。【方法】选用粉末状水淬渣(S1)、粒状水淬渣(S2)和空气冷却粒状钢渣(S3)为研究对象,分别设置在土壤水溶液以及纯蒸馏水中培养97天,并设置35℃和25℃两个培养温度。定期离心取上清液,取样后补充水分继续培养,直至培养结束。【结果】钢渣在土壤溶液中培养,第一天的硅素释放主要由钢渣冷却方式决定,而在以后的培养过程中主要受温度的影响,其次为钢渣粒径;硅素累积释放量与时间的关系可以用幂函数方程y=kxm来拟合;35℃培养97天后,S1、S2与S3钢渣硅的溶出率(累积硅释放量与有效硅的比例)分别为37.3%、30.3%与27.3%;在25℃培养下,S1、S2与S3钢渣硅的溶出率分别为14.3%、7.9%与10.2%。钢渣在纯蒸馏水的培养中,第一天钢渣硅释放主要受温度的影响,而在以后的培养过程中主要受钢渣粒径的影响,温度和钢渣冷却方式对其影响甚微;硅素累积释放量与时间的关系可以用线性方程y=ax+b来拟合;在35℃,S1、S2与S3钢渣硅的溶出率分别为0.22%、0.16%与0.16%。在25℃培养下,S1、S2与S3钢渣硅的溶出率分别为0.17%、0.13%与0.14%。钢渣在土壤溶液培养,25℃培养67天,加入钢渣提高了土壤浸提液的p H值,但之后与CK基本相同;在35℃培养下,加入钢渣的土壤浸提液p H值总体都要显著高于CK处理。纯水培养介质中,两种温度培养下,在同一阶段S1浸提液的p H和EC值都要显著高于S2和S3,温度对p H和EC的影响不显著。【结论】钢渣硅素释放规律主要受培养介质和温度的影响,粒径有一定的影响。在土壤溶液中钢渣硅素释放显著高于在蒸馏水中,35℃比25℃更有利于硅素的释放,粉末状比粒状更有利于硅素的释放。由此认为,钢渣作为硅钙肥在大田施用时,将钢渣磨细做成粉末状产品,施用时随翻耕埋入土壤,初春采用保温措施等都有利于提高钢渣中硅的利用效率。
【Objectives】The release character of Si form the slag- based Si fertilizer affects the efficiency of Si fertilizer,which might be governed by the cooling process and granular size of slag. So the study on the Si- release characters of slag- based Si- fertilizers will provide basis for their field application. 【Methods】Three different types of steel slag,including S1( in powder form,water- cooling),S2( in granular form,water- cooling),and S3( in granular form,air- cooling) with identically available Si content,were used for incubation trial in both soil suspension and distilled water media at 35℃ and 25℃. Leaching solutions were collected through centrifugation atregular intervals. After centrifugation,samples were added with quantitative amount of water and incubated sequentially till the trial end.【Results】In the soil suspension- incubation experiment,the rate of Si released from slag in the first day was mainly influenced by slag cooling process,but was impacted principally by temperature and granular size of slag as the experiment later on. The relationship between the cumulative Si release and time could be expressed with the exponential equation: y = kxm. After 97 days of soil incubation,the Si- releasing percentage( the ratio of cumulative Si release to total available Si content) of S1,S2 and S3 were 37. 3%,30. 3% and 27.3%,respectively,at 35℃,and 14. 3%,7. 9% and 10. 2% at 25℃. In distilled water- incubation experiment,the first day release of Si was mainly influenced by temperature,afterwards principally by granular size of slag,never by slag cooling process. The relationship between the cumulative Si release and incubation time could be expressed with linear equation( y = ax + b). After 97 days incubation in water,the Si- releasing percentages of S1,S2 and S3 were 0. 22%,0. 16% and 0. 16%,respectively,at 35℃,and 0. 17%,0. 13% and 0. 14% at25℃. In the soil suspension- incubation experiment,the p H values of leaching solutions from the soils added with steel slag were increased in the first 67 days incubation period,then their p H values were kept similar with CK at25℃,but the p H values of treatments were always higher than that of CK throughout the whole incubation period at35℃. In the distilled water- incubation experiment,p H and EC of S1 were significantly higher than those of S2 and S3 within the same incubation period,temperature did not show much impact on p H and EC.【Conclusions】Si- releasing characteristic of slag was principally influenced by incubation medium and temperature,followed by particle size of slag. Si- releasing rate was significantly higher in the soil- incubation condition than in the distilled water- incubation condition. High temperature and fine particles are good for the release of Si. Therefore,steel slag is recommended to be completely pulverized before application into soil.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2015年第2期500-508,共9页
Journal of Plant Nutrition and Fertilizers
基金
国家“十二·五”科技支撑计划“钢渣农业资源化利用技术研究与示范”(2013BAB03B02)
国家自然基金“秸秆还田对我国南方典型水稻土壤硅素释放过程影响的定量研究”(41301310)资助
关键词
钢渣
培养
温度
粒径
冷却方式
硅释放
steel slag fertilizer
incubation
temperature
particle size
cooling process
silicon-release