Fundamental Technology Study On Agriculture Utilization Of Solid Waste From Iron And Steel Industry

The synthesize Utilization of solid waste is an effective method to develop cycling economy. And it is also an urgent need to carry out the economy developing with good quality and high speed. It can be an effective solution to the contradiction between resource shortage and economic development, which can increase the economic benefit and reduce the pollution to environment.Blast furnace slag is the main solid waste which discharged from the steel-making process. In order to solve the problems exist in the resource utilization process of blast furnace slag in china, slag utilization ways should be developed. And the slag can be made to new fertilizer for agriculture, which can promote the sustainable development of steel industry and agriculture. In this dissertation, preparation technology of slow-release silicon-potassium fertilizer which used the desiliconization slag as the mainly material was studied. The contents of the research are organized as follows.Firstly, Silicon-potassium fertilizer samples were synthesized with difference K2O content, which were 15%, 20%, 25% and 30%. The crystal performance, microcosmic structure, dissolving character and corrosion resistance performance to refractory materials of silicon-potassium fertilizer samples with difference synthesize such conditions as K2O content, heat temperature, heat preservation time, cooling mode and joined substance was observed. The experiment results showed that the synthesize conditions had no obvious influence on the crystal performance and microcosmic structure of the silicon-potassium fertilizer. All of the chemicals which include K in the fertilizer were existed in non-crystal state. And the silicon-potassium fertilizer has obvious slow-release character and corrosion performance.Secondly, the orthogonal experiment design and neural network methods were used to optimize the reaction condition for silicon-potassium fertilizer production. In this study, the initial stage stop method was used to remedy data, which could increase the network generalization ability obviously. The result showed that 1400℃, the content of K2O about 20% and heat preservation 15 minutes is the best reaction condition for silicon-potassium fertilizer.Thirdly, based on the precondition that the best reaction condition was decided, mathematic programming method was used to analysis the specific phases of synthesizing flow of silicon-potassium fertilizer. An optimization model was established whose objective function was economic benefit maximization or economic losing minimization. Then, the resolution method for the optimization model was discussed to optimize the technics flow for using desiliconization slag to produce silicon-potassium fertilizer in industrialization.At last, agricultural experiments were carried out to study the effect of silicon-potassium fertilizer on crop yield, quality and soil. The agricultural experiments showed that not only the crop output was increased but also the content of K in the soil was also increased and the influence on the pH value of the soil is weak. In order to evaluate the environmental and economic benefit of silicon-potassium fertilizer, the green accounting method was used. The results showed that if it was only evaluated based on economic output, the silicon-potassium fertilizer could replace the traditional quick result fertilizer and has better effect.