Development And Application Of New Type Granulation Binder For Organic Compound Fertilizer Based Compost

Now it was quite wide that inorganic mineral binders were used to granulation of organic compound fertilizer, but they had began to restrict development of high nutrient granular organic compound fertilizer increasingly for their inevitable shortcomings, which had more dosages, low granulation rate and high rate of return product and so on. This thesis conducted a series of study on aspects of new type binders and their granulation effect etc. The research results showed that crude corn starch was unfit to be used as binder in granulation of organic compound fertilizer directly for its more dosages, low granulation rate and high rate of return product. Its granular of resistance forces to crushing was short of Chinese National Standard (GB15063-94). Its granular size was mostly less than 2mm, and there were more granules bigger than 6mm to be returned product. Three starch adhesives, which were separately liquid high Fe binder (NJJ), starch binder modified with polyvinyl alcohol (PMS), and dry powder starch adhesive (DPS), were obtained through cornstarch modified by the way of chemistry. Three organic binders all had no direct toxicity for living things, could be biodegraded and had very good storage ability under normal temperature (25℃). The storage period of NJJ and PVA was no less than 60 days, and DPS's was more than 180 days. Three binders' granulation rates were more than 93%. Their return product rates were less than 12%. And their dosages all not exceeded 1%. Their average granular resistance forces to crushing were greater than 10N, which had advantage over the National Standard. Their disintegration rates all were 0 after 24h wet steeped. To compare the granulation character of three organic binders with the granulation character of inorganic binder, three organic binders had the advantages of less dosage, high granulation rate and low rate of return product. Disintegration rate of inorganic binder was higher 6.6% than that of organic binders. For any liquid organic binder, its quantity of return products that was greater than 6mm would reduce obviously if its viscosity decreased or diluted. For the dry powder adhesive, its granulation capability of the binder processed by wet method was greatly better than that of the binder processed by dry method. The drying character of granular fertilizers made by organic binders had advantage over the inorganic binder. It was completely practicable that modified starch adhesive was used to granulation of organic compound fertilizer. And they could be used to process granular organic compound fertilizer of high nutrient concentration.Nutrient preliminary solubility of all granular organic compound fertilizers was less than 40%. Comparison between organic binder and inorganic binder, organic binder was able to delay nutrient release of N, P and K in granular organic compound fertilizer obviously, especially the effect of delaying P release was most obvious. The PMS had the best effect on delaying the release of nutrient in organic compound fertilizer. The result of leaching examination showed that organic binder was better in favor of delaying nutrient release than inorganic binder. This illuminated that organic binder was good material to develop new type non-envelope control release fertilizer, and nutrient controlled release was achieved by the way of granulation at one time. The result of open field examination indicated that crops special granular organic compound fertilizerwas able to accelerate plant's grow, reduce nitrate content of crop esculent part and increase quality and in yield obviously. Special organic compound fertilizer had advantage over traditional fertilizer and equal nutrient chemical fertilizer on aspect of increasing crop yield obviously. Compared to inorganic binder, organic binder could decrease Y24~37 RMB/t cost of organic compound fertilizer during granulation obviously. Per ton granular organic compound fertilizer was able to increase the profit of $130 RMB averagely, which would be able to gain favorable benefit of economy, environment and society.