Formation cause,composition analysis and comprehensive utilization of rare earth solid wastes

Based on practical situation of rare earth industrial chain,production process and rare earth materials that could produce solid wastes on batch were discussed.Formation cause,formation volume,composition analysis and comprehensive utilization of the solid wastes of rare earth hydrometallurgy slag,electrolysis slag,Fe-based rare earth permanent magnetic materials,Co-based rare earth permanent magnetic materials,rare earth hydrogen storage materials,rare earth polishing powders and rare earth catalysts were comprehensively introduced.Besides,some suggestions on treatment and administration on rare earth solid wastes were put forward.

Prospects of utilization of waste dumped low-grade limestone for iron making: A case study

Low grade dumped limestone sample having high silica of 8.1%, 36.8% CaO, and 3% Al2O3 has been studied with the aim to reduce the silica level to below 3% for its utilization in iron making. Beneficiation study of the sample was initiated with desliming of the feed sample of -100 μm to remove the siliceous ultrafine particles and to improve the feed quality. Flotation study was carried out by column flotation technique varying the collector dosage, superficial air flow velocity and froth depth to assess their effect on silica reduction and CaO recovery. It was observed that increased collector dosage and superficial air velocity increases the recovery of CaO, and increase in the froth depth reduces the mass flow and silica content in the concentrate. The best result was found at 1.25 cm/sec superficial air velocity, 25 cm froth depth, 1.25 kgpt collector dosage and concentrate assayed 47.3% CaO, 2.8% silica with 72% CaO recovery.

Technology of comprehensive disposal and utilization of municipal solid waste (MSW)

The project for treating MSW of 200 tons each day was built in Yibin, Sichuan Province of China. The disposal processes are: separation and selection of usable resources; compost and fermentation of “heavy” organic waste (kitchen, garden composting rubbish); incineration of “light” waste (plastic, paper, wood and bamboo etc.) and landfill of inorganic waste. The thermal energy generated in the process can be used as 1/3 of the whole energy for drying fertilizers. In the process, there is no wastewater drainage, and air emissions can be effectively controlled by a series of measures. The sanitary and environmental indicators of disposal site meet the national standards. This project has worked well for two years. It not only disposes of and reduces the MSW, but also retrieves the resource effectively. The organic fertilizer has been applied in the ten thousand acres of fields, with productivity increase by more than 10%.

Advances in Utilization of Agricultural Waste Based on Production of Edible Fungi

Along with the rapid development of edible fungus industry in China,the traditional mode of production giving priority to wood chips will be severely limited,and using agricultural waste distributed widely,having large yield,and containing high content of organic matter to produce edible fungi has good economic and ecological benefit. In this paper,based on the analysis of characteristics of agricultural waste in China,the present situation of application of agricultural waste in the production of edible fungi at home and abroad was introduced,and the main problems existing in production of edible fungi by using agricultural waste in China at the present stage were pointed out. Finally,the development direction of using agricultural waste to cultivate edible fungi was discussed,and some suggestions were put forward,such as improving the theoretical system for using agricultural waste to produce edible fungi,and establishing the standardized technical system for using agricultural waste to produce edible fungi.

Integration of Low-level Waste Heat Recovery and Liquefied Nature Gas Cold Energy Utilization

分别地，二个新奇热周期基于 Brayton 周期和 Rankine 被建议它集成低级废热和液化性质气体(LNG ) 的恢复为发电的冷精力利用。在低级废热，低温度的 exergy 和 LNG 的压力 exergy 通过系统合成高效地被利用的地方，精力的串联利用在二个热周期被认识到。模拟加 10.2 用商业白杨被执行，并且结果被分析。与常规 Brayton 周期和 Rankine 相比，二个新奇周期在 exergy 效率带 60.94% 和 60% ，分别地并且 53.08% 和 52.31% 在热效率分别地。

Thermal treatment and utilization of Al-rich waste in high calcium fly ash geopolymeric materials

The Al-rich waste with aluminium and hydrocarbon as the major contaminant is generated at the wastewater treatment unit of a polymer processing plant. In this research, the heat treatment of this Al-rich waste and its use to adjust the silica/alumina ratio of the high calcium fly ash geopolymer were studied. To recycle the raw Al-rich waste, the waste was dried at 110°C and calcined at 400 to 1000°C. Mineralogical analyses were conducted using X-ray diffraction (XRD) to study the phase change. The increase in calcination temperature to 600, 800, and 1000°C resulted in the phase transformation. The more active alumina phase of active θ-Al2O3 was obtained with the increase in calcination temperature. The calcined Al-rich waste was then used as an additive to the fly ash geopolymer by mixing with high calcium fly ash, water glass, 10 M sodium hydroxide (NaOH), and sand. Test results indicated that the calcined Al-rich waste could be used as an aluminium source to adjust the silica/alumina ratio and the strength of geopolymeric materials. The fly ash geopolymer mortar with 2.5wt% of the Al-rich waste calcined at 1000°C possessed the 7-d compressive strength of 34.2 MPa.

Pathways for Sustainable Utilization of Waste Chicken Eggshell

Chicken eggshell is one of the most common wastes generated from households,restaurants and other food processing outlets.Waste Chicken Eggshells(WCES)also constitutes an environmental nuisance and ends up discarded at dumping site with no consideration of further usage.The main constituent of WCES is calcium carbonate from which calcium or calcium oxide can be extracted for various applications.This current effort reviews recently published literature on the diverse applications of WCES.The considered utilization avenues include catalysts for biofuel production,construction industry,wastewater purification,industrial sector,food industry,medical,and agricultural applications.The specific areas of application apart from the transesterification reactions include cement additives and replacement in concrete,asphalt binder,adsorbent of metals and dyes,production of hydroxyapatite,food supplement and fortification,dentistry,therapeutics,bone formation,drug delivery,poultry feeds as well as organic fertilizer.For most of the identified applications,the WCES is subjected to pretreatment and other modification techniques before utilization.The conversion of WCES to valuable products is a cost-effective,safe,environmentally friendly,non-toxic and viable means of waste disposal and utilization.More investigations are needed to further explore the benefits derivable from this bioresource.

Analysis of Comprehensive Utilization of Coconut Waste

This paper describes and analyzes the coconut cultivation in China,and the current comprehensive utilization of waste resources generated during cultivation and processing of coconut.The wastes generated in the process of cultivation include old coconut tree trunk,roots,withered coconut leaves,coconut flower and fallen cracking coconut,mainly used for biogas extraction,direct combustion and power generation,brewing,pharmacy,and processing of building materials;the wastes generated during processing include coconut water,coconut coat,coconut shell and coconut meal,mainly used for processing beverages,pharmaceutical products,activated carbon,medium and feed.This paper analyzes and explores some problems in the process of comprehensive utilization of coconut waste in China,such as insufficient understanding,inadequate development and lack of research efforts,and finally puts forth the corresponding development countermeasures.

A Promising Way of Resource Utilization in China: Converting Waste Oils and Fats to Biodiesel

Most of Biodiesel, a clean burning alternative fuels for diesel engines is made from renewable agricultural feedstock, such as rapeseed oil, soybean oil etc., but less expensive biodiesel can also be made from waste oils and fats, including recycled restaurant grease and animal fats. Because of the eating habit of the nation and diet culture in china,?restaurant-kitchen garbage is increasingly serious and has negative impact on environment and food security. The utilization of waste oils and fats to biodiesel provide a promising way of how to appropriately and effectively dispose of restaurant-kitchen garbage. This paper first reviews the development status of biodiesel industry, then introduces the novel technology of tubular reaction for producing biodiesel from waste oils and fats on the typical industrialization case in Kunshan. All these efforts are expected to provide a viable development path for our waste oil to produce biodiesel and worth reference to waste oils and fats recycling and reuse.

Utilization of Coal Ash as a Barrier Material for Radioactive Waste Disposal

About 10% of total electricity (386 MkW) was generated by nuclear power plants in the world (2014) and about 58,400 tons of uranium has been mined in uranium mines annually. A plenty of radioactive waste material is produced from uranium mines and nuclear power plants. The wastes must be disposed or stored safely for a long term. Because if they leak and/or move from disposal or storage sites due to air/groundwater flow, then a serious environmental pollution can occur. Hence, multi-layer system has been proposed and employed in order to seal off these radioactive waste materials from biosphere. Basically, bentonite is now used for establishing one of absorbing and sealing layers in this system. However, the amount of high quality bentonite is very limited and in some cases it is hard to be obtained. On the other hand, a great deal of refuse from coal burning plants is produced every year and the amount of it is expected to be higher each year especially in developing countries. More than half of coal ash is utilized and the remaining is disposed at the disposal sites. However, the life of the disposal site is limited and it is difficult to find a new disposal site. It is requested that the percentage of the utilization of the coal ash be increased in every field. From the above two points of view, a fly ash-based barrier system is considered in this research and this paper discusses the applicability of fly ash as a content of barrier material. Based on the results of a series of laboratory tests, it can be concluded that fly ash has a potential for use in the buffer material as the bentonite is substituted.

Potential Utilization of Sawdust in Energy, Manufacturing and Agricultural Industry;Waste to Wealth

Sawdust which is basically considered as?a timber-industrial waste?that pollutes the environment can become a valuable commodity which is considered in three ways: Manufacturing, Energy and Agricultural utilization. The sawdust is burnt in an updraft gasifier under a limited supply of air to obtain?producer gas which is carbon II oxide and hydrogen as main components. The sawdust and other biomass materials are mixed in certain proportions, then bound together and palletized to a small blocks called briquettes. The material?was also considered to be composted by mixing it with animal digestion or?wood ashes and calcium carbonate to form fertilizers. The sawdust and wood shavings can be used for particle board as well as oil production.

Study on the Optimized Combination and Utilization of Waste Resources of Agriculture and Animal Husbandry in Tibet

With the high-quality development of modern agriculture and animal husbandry in the plateau,the waste resources produced by agriculture and animal husbandry show a trend of diversification.How to effectively carry out the key work based on the optimal combination and utilization of waste resources of agriculture and animal husbandry in Tibet is imminent.To realize efficient recycling of waste resources of agriculture and animal husbandry,innovative mode is explored.On the theoretical basis,it can effectively alleviate the resource crisis,control the pollution sources,effectively utilize the resources and construct the recycling mode,which plays an important role in promoting,integrating and coordinating the high-quality development of modern agriculture and animal husbandry in the plateau.In this paper,optimal combination and utilization manner of waste resources of agriculture and animal husbandry under the circular development concept is comprehensively analyzed and summarized,to continuously improve reasonable and effective utilization level and efficiency of agricultural waste resources.It could not only inhibit waste pollution but also promote rational and effective utilization of resources,thereby laying theoretical basis for sustainable and efficient development of agriculture and animal husbandry in Tibet,promoting the improvement of agricultural and rural ecological environment,and providing the thinking for exploring model of ecological recycling in plateau.

Utilization of waste polyethylene terephthalate as a reducing agent in the reduction of iron ore composite pellets

The increasing consumption of plastics inevitably results in increasing amounts of waste plastics. Because of their long degradation periods, these wastes negatively affect the natural environment. Numerous studies have been conducted to recycle and eliminate waste plastics. The potential for recycling waste plastics in the iron and steel industry has been underestimated; the high C and H contents of plastics may make them suitable as alternative reductants in the reduction process of iron ore. This study aims to substitute plastic wastes for coal in reduction melting process and to investigate their performance during reduction at high temperature. We used a common type of waste plastic, polyethylene terephthalate(PET), because of its high carbon and hydrogen contents. Composite pellets containing PET wastes, coke, and magnetite iron ore were reduced at selected temperatures of 1400 and 1450°C for reduction time from 2 to 10 min to investigate the reduction melting behavior of these pellets. The results showed that an increased temperature and reduction time increased the reduction ratio of the pellets. The optimum experimental conditions for obtaining metallic iron(iron nuggets) were reduction at 1450°C for 10 min using composite pellets containing 60% PET and 40% coke.

Resourceful Utilization of Tannery Wastewater

Leather industry is an important light industry in China.Leather making requires a series of chemical treatment.Degreasing,unhairing and chrome tanning wastewaters are the main portions of tannery wastewater.Reclaiming and reusing these wastewaters can eliminate 80% of COD,75% of BOD,95% of chromium and 93% of sulfuret,furthermore reduce environment impact,decrease treatment costs,save chemicals and water.Some application methods of wastewater reclamation and reuse for different operations were reported.The suitable reclamation and reuse technologies can enable leather making processes more rational,and realize the recovery and recycle of several chemicals in the tannery.Resourceful utilization of tannery wastewater should mate with renovating production technology,updating equipment,and must be guaranteed sufficiently by environmental protection measures.

Current Situation and Suggestions for Energy Utilization of Agricultural Waste in Hubei Province

Energy utilization is high-value use pattern of agricultural waste,and is main development direction of agricultural biomass energy industry in China.Planting and breeding industry in Hubei Province occupies important position in whole country.Agricultural waste resources are rich,and it has huge potential for developing agricultural biomass energy.By statistical data during 2000-2011,we analyzed current situation and problem for energy utilization of agricultural waste in Hubei Province,and put forward several countermeasures and suggestions,vigorously promoting energy utilization of agricultural waste.

Whole process reclamation and utilization of wastes produced in the biological fermentation industry

Wastes yielded in the vintage process and the biological fermentation of itaconic acid and sodium gluconate of a winery in Shandong, such as grain stillage, melon lees, cornstarch protein residues, itaconic acid mother liquid, itaconic acid mycelium and sodium gluconate mycelium, were studied. High-activity biological protein feed, foliar fertilizer and irrigation fertilizer were generated from these wastes by applying biological/microbial technologies. Meanwhile, a whole set of technological pathways was put forward. As a result, the optimal economical and social benefits can be obtained with low natural resource consumption and environmental costs by converting wastes into useful matters. In conclusion, through the utilization of limited resources in the whole process of reclamation and utilization of wastes, the harmony promotion can be achieved between the economic system and the natural ecosystem.

Treatment and Resource Utilization of Deinking Sludge from Regenerated Paper Mill

To fully utilize secondary resources,it will inevitably generate a large amount of deinking sludge using waste paper as raw material for paper making.The sludge contains small fibers and dissolved substances of various chemicals.After adding flocculant and settling treatment,deinked sludge is formed.However,its organic matter content can reach a high level of 40%to 50%,and it can also be reused,effectively avoiding the harmful impact of papermaking sludge on the environment.

Utilization of α-olefins obtained by pyrolysis of waste high density polyethylene to synthesize α-olefin-succinic-anhydride based cold flow improvers

浪费聚合物热分解获得的石蜡富人烃部分的利用的一条新线路被调查。-olefin-succinic-anhydride 基于中介倒点镇静剂添加剂因为柴油被综合，在哪个反应需要的石蜡被废物的热分解获得高密度的聚乙烯(HDPE ) 。石蜡的部分被塑料废物的de聚合在 500 滓鲥?在一个试管反应堆生产???????????????????????禧?????迋????骤??????吗鲥??????禧哉????嫪????滓?????篤?廯??????可??????????????裍??妢???????臙???????蚨?蚨？？

Synthesis of Activated Carbon from Polyethylene Terephthalate(PET)Plastic Waste and Its Application for Removal of Organic Dyes from Water

Synthetic plastics are often considered to be materials that cannot be broken down by natural processes.One such plastic,polyethylene terephthalate(PET),is commonly used in everyday items but when these products are discarded,they can cause serious harm to the environment and human health.In this study,PET plastic waste was used to create activated carbon using a physical activation process that involved using CO2 gas.The researchers investigated the effects of different temperatures,carbonization,and activation times on the resulting activated carbon’s surface area.The activated carbon was then analyzed using scanning electron microscopy(SEM),X-ray diffraction(XRD),FTIR,and BET.The activated carbon created from PET plastic waste showed excellent absorption properties for methylene blue in aqueous solutions across a wide range of pH levels.By creating activated carbon from plastic waste,not only are environmental issues addressed,but high-value activated carbon is produced for environmental remediation purposes.