As a result of rice grain processing, a big amount of waste (up to 20%) is produced. It is mainly rice hulls. The main components of rice hulls are cellulose, lignin and mineral ash. The mineral ash quantity in rice hulls varies from 15 up to 20%, by weight of the rice hulls. The mineral ash consists of amorphous silica (opal-type). Due to the high content of silica in rice hulls, the material burns with difficulty under natural conditions, and it is biodegradably destroyed only with difficulty, when composted. Utilization of rice hulls then becomes an ecological problem due to huge rice production and its continuous growth. At the same time, the annual quantity of silica content in rice hulls is comparable with the quantity of amorphous silica produced as a mineral resource. The issue of manufacturing cellular glass silica construction materials from rice hulls as a renewable resource is discussed in this paper. The utilization technology is based on an amorphous silicon oxide with the use of energy from the combustion of the organic component of rice hulls.

No abstract

No abstract

The paper analyzes a solution in green manufacturing of foamed or cellular ceramics. The objective of this study was to determine the technical solution for rice husk ash and “tales” of mixed glass cullet reusing based on the specific properties of these materials for creation of spherical holes inside ceramic using the process of coalescence of cellular glass. The paper reports on experimental results obtained from the production of lightweight cellular glass granules produced using glass cullet and rice husk ash. Lightweight cellular glass granules were mixed with clay, pressed and fired in air at 920°C. Clay sintering and the formation of ceramic were followed with the coalescence of cellular structure of glass granules and with the formation of spherical hollows inside the matrix. Density and strength of the fired ceramic bodies were determined. It is observed that the lightweight ceramics with density 900 ÷ 920 kg/m3 possess a compressive strength of about 5 MPa that is acceptable for bricks or tiles manufacture. The utilization of amorphous silica waste for lightweight ceramics manufacture helps in reducing waste disposal concerns and costs associated, and also transforms the waste into an alternative raw material with added value, moreover making the final product cheap.

Coal mining is accompanied by bulk waste formation in form of spoil heaps from low quality ore. As a result of aggressive natural factors impact specific mineral and chemical composition of rocks, which forms spoil heaps, leads to the environmental man-caused load in form of dust and gas emission, water pollution and adjacent area littering. Thus, lands, where spoil heaps are disposed, are excluded from economic use, and their resource potential gets lost because of wind and water erosion, negative physical, chemical and biochemical processes, and transformation of rocks, which forms spoil heaps, that causes the reduction of its value as secondary resources. It defines the urgency of developing methods aimed at the lowering of ecological load, caused by spoil heaps, to acceptable level and at the preservation of its resource potential as artificial deposits. One of the possible solutions is to fill underground worked-out mine area with stowage materials using low quality ore. But this technology pushes up the cost of coal production and is not applicable to new coal mining objects, which has lack of free worked-out area as well as to waste dumps, accumulated during long years of coal production. One of the most common ways of reducing the negative impact on the environment of already formed spoil heaps is its recultivation. However, recultivation of coal mining waste, which is followed by application of antipyrogens, ameliorants and mineral fertilizers to waste dumps, considerably limits their further utilization as artificail deposits. Antipyrogens, ameliorants and mineral fertilizers, when entering into physical and chemical reactions with coal mining waste, make this waste unsuitable for application as a secondary resource, particularly during the production of many construction materials. It defines the prospectivity of spoil heaps conservation, which allows not only to reduce the negative impact of spoil heaps on the environment but also to preserve their resource potential. This study offers a method, a technology and technical solutions for spoil heaps conservation that ensure their geoecological safety as sources of environmental pollution and allow to use its resource potential for production of target products. Ключевые слова:терриконики, экологическая тех-ногенная нагрузка, эрозия, вы-бросы в атмосферу, геоэкологи-ческая безопасность, рекульти-вация, техногенные месторож-дения, ресурсный потенциал, консервация, технические реше-ния, геосинтетические материа-лы, бентонитовые маты, отло-женный спрос, строительные ма-териалы, строительная керамика, энергоэффективные добавки.Добыча угля сопровождается образованием крупнотоннажных отходов в виде террикоников из некондиционной руды. Специфический минералогический и химический состав пород, слагающих терриконики, в результате воз-действия агрессивных природных факторов приводит к формированию экологической техногенной нагрузки на окружающую среду в виде пылевых и газовых выбросов, образования загрязненных вод, загрязнения и засорения прилегающих территорий. ...