废白土在天然橡胶中的应用性能

研究了废白土做填充剂及软化剂在天然橡胶中的应用,并与同份数的陶土（同时添加3份芳烃油）进行性能对比。结果表明：废白土可以作为填充剂和软化剂应用于天然橡胶中,且以废白土为填料的胶料流动性、焦烧性、扯断永久变形性能好、耐磨耗性能、冲击弹性、伸长率、耐老化性能均好。     

Precipitation characteristics of palladium from a simulated radioactive liquid waste by Ascorbic Acid

The precipitation characteristics of palladium (Pd) from a simulated radwaste solution by ascorbic acid was investigated. Pd was selectively precipitated by the reduction reaction of Pd with ascorbic acid. When the nitric acid concentration in the 8 component system was below 2.0 M, Pd over 99.5 % was selectively precipitated at an ascorbic acid concentration above 0.06 M, while other elements mainly remained in solution. The precipitation yield of Pd by ascorbic acid decreased with the increase of the nitric acid concentration.     

工业废料加固土的试验研究

利用炉渣和粉煤灰等废渣、并掺入适量水泥或石灰等胶凝剂来加固土壤，可以节约工程造价、改善环境。分别以水泥、石灰、水泥 石灰混合料加固由粉煤灰、粘土、细砂、淤泥．炉渣以不同配比组成的三种复合土，每种拌合物以相同的加水量分别制备3组试件．自然条件下养护3d．7d．28d后进行无侧限压强度试验、结果表明：A型复合土单掺水泥的加固效果最为显著，其早期和28d强度值均随水泥掺量的增加而显著提高；c型土则单掺石灰的效果最好．最佳掺量为15％；等量复掺“水泥 石灰”时．对B型土的加固效果最好，这说明掺入一定的水泥或石灰或同时加入水泥和石灰加固由粉煤灰，炉渣、软粘土、淤泥和细砂组成的复合土在技术上是可行的．     

Modelling of long-term diffusion–reaction in a bentonite barrier for radioactive waste confinement

Bentonites have been proposed as buffer material for barriers in geological disposal facilities for radioactive waste. This material is expected to fill up by swelling the void between the canisters containing the waste and the surrounding ground. However, the bentonite barriers may be submitted to changes of humidity, temperature variation, fluid interaction, mass transport, etc. This could modify the physico-chemical performance of the barrier, mainly on the interface with the steel container and with the geological barrier. The engineered barrier development necessitates thus the study of the physico-chemical stability of its mineral component as a function of time under the conditions of the repository in the long-term.The purpose of the present study was two-fold. Firstly, it was hoped to simulate the chemical transformations (geochemical and cation exchange reactions) coupled with diffusion of chemical-elements into the engineered barrier under repository conditions by applying a thermokinetic hydrochemical code (KIRMAT: Kinetic Reactions and Mass transport).Secondly, it was hoped to apply a simplified method to estimate the swelling capacity evolution by a volume balance in the fluid-saturated engineered barrier, considering that the decay of swelling capacity is directly proportional on the volume of transformed montmorillonite and, taking into account that it may be partially compensated by the volume of neo-formed swelling clays.The system modelled herein was considered to consist of 1-m thick zone of water-saturated engineered barrier. This non-equilibrated system was placed in contact with a geological fluid on one side, which was then allowed to diffuse into the barrier, while the other side was kept in contact with a source of metallic iron. Reducing initial conditions(P_O2 0; Eh = − 200 mV) and a constant reaction temperature (100 °C) were considered.The results showed that the EB in contact with the geological fluid was highly transformed after 10,000 years, whereas the most significant chemical processes were illitization, cation exchange and saponization, extending up to 20 cm into the EB. Chemical transformations of minor importance in the EB were identified as well, such as a neo-formation of silicates (quartz, cristobalite), anhydrite, laumontite, magnetite and chlorite in the system.A simplified method based on volume balance showed that the swelling capacity of the bentonite barrier is slightly affected after 10,000 years of diffusion–reaction (D close to 1) because the volume of neo-formed swelling-clays is almost directly proportional to the volume of transformed Na/Ca-montmorillonite, except for a strong illitization and/or neo-formation of non-swelling clays. In the present study, this simple approach predicted that the decay of swelling capacity of the engineered barrier is drastically affected close to the geological barrier-engineered barrier interface. Out this zone the swelling capacity decay lies between 5% and 11%.     

Microstructural evaluation of a clay ceramic incorporated with petroleum waste

In this work an extensive SEM/EDS microstructural investigation associated with technological properties was carried out on kaolinitic clay bodies incorporating different amounts, up to 20 wt.%, of a bentonite-treated petroleum waste. The clay bodies were fired at temperatures from 850 to 1100 °C and then bend tested until rupture. Fracture surface observation revealed the existence of relatively small BaSO₄ particles that do not significantly contribute to the rupture process. By contrast, larger clay matrix embedded particles and voids exert more influence on the ceramic rupture. Since these particles are also normal features in waste-free clay bodies, the incorporation of bentonite-treated petroleum waste cannot be directly related to the rupture process. Exception occurred above 10 wt.% added waste and temperatures higher than 1000 °C, at which the comparatively higher amount of non-plastic quartz particles plays a role in the decrease of strength.     

Calcium sulfoaluminate cement blended with OPC: A potential binder to encapsulate low-level radioactive slurries of complex chemistry

Investigations were carried out in order to solidify in cement a low-level radioactive waste of complex chemistry obtained by mixing two process streams, a slurry produced by ultra-filtration and an evaporator concentrate with a salinity of 600 gxL^− 1. Direct cementation with Portland cement (OPC) was not possible due to a very long setting time of cement resulting from borates and phosphates contained in the waste. According to a classical approach, this difficulty could be solved by pre-treating the waste to reduce adverse cement–waste interactions. A two-stage process was defined, including precipitation of phosphates and sulfates at 60 °C by adding calcium and barium hydroxide to the waste stream, and encapsulation with a blend of OPC and calcium aluminate cement (CAC) to convert borates into calcium quadriboroaluminate. The material obtained with a 30% waste loading complied with specifications. However, the pre-treatment step made the process complex and costly. A new alternative was then developed: the direct encapsulation of the waste with a blend of OPC and calcium sulfoaluminate cement (CS̄̄A) at room temperature. Setting inhibition was suppressed, which probably resulted from the fact that, when hydrating, CS̄̄A cement formed significant amounts of ettringite and calcium monosulfoaluminate hydrate which incorporated borates into their structure. As a consequence, the waste loading could be increased to 56% while keeping acceptable properties at the laboratory scale.     

Use of ground clay brick as a pozzolanic material to reduce the alkali-silica reaction

The objective of this experimental study was to use ground clay brick (GCB) as a pozzolanic material to minimize the alkali-silica reaction expansion. Two different types of clay bricks were finely ground and their activity indices were determined. ASTM accelerated mortar bar tests were performed to investigate the effect of GCB when used to replace cement mass. The microstructure of the mortar was investigated using scanning electron microscopy (SEM). The results showed that the GCBs meet the strength activity requirements of ASTM. In addition, the GCBs were found to be effective in suppressing the alkali-silica reaction expansion. The expansion decreased as the amount of GCBs in the mortar increased.     

Soil clay mineralogy in relation to fertility management: Effect of soil clay mineral composition on potassium fixation under conditions of upland rice soils

Since K fixation in soils is largely a function of clay mineralogy, an effort was made to elucidate the influence of mineralogical variations in soil clays on K fixation, under the moisture-temperature regimes usually prevalent in tropical upland rice soils. Beidellitic clay turned out to be the most severe fixer of addedK (80%), followed by vermiculitic (69%) clays. Fixation is not appreciable (< 15%) in clays consisting of montmorillonite, x-ray amorphous material, chlorite, hydrous mica, kaolinite and halloysite. Fixation by beidellite and vermiculite clays is reduced by the simultaneous occurrence of other mineral species.     

Rheological studies on a slurry biofuel to aid in evaluating its suitability as a fuel

Biomass is an often abundant, renewable, low ash and low sulfur fuel. Due to these properties, biofuels are promising alternatives for traditional petroleum-based fuel applications; however, traditional biofuels for internal combustion engines are not cost competitive with gasoline, diesel or fuel oils. One method to reduce the cost of biofuels is to use slurry fuels which have a potential lower cost than liquid biofuels due to high conversion efficiencies. Slurry biofuels, such as a mixture of corn and water, could provide a biofuel alternative for diesel engines, pressurized gasifiers and heating oil applications such as burners or gas turbines. Use of these biomass slurries poses important questions about their stability and suitability for practical applications in internal combustion engines and combustors.This work reports rheology data for stable corn-starch water slurries (CSWS) which used a polyacrylic acid thickener to eliminate settling of the slurry and to provide desirable shear-thinning behavior for most of the compositions evaluated. The effect of shear rate on the viscosity of the CSWS was studied using a BOHLIN-controlled stress (CS) rheometer. The well-known Ostwald—de Waele power law and Sisko models for viscosity fit the data. The effect of corn starch content, thickener content and temperature on the viscosity of CSWS was also studied. The favorable shear thinning properties were observed for starch contents up to 45% starch and should aid pumping, injection and spraying. The lower heating values of the slurries, however, are undesirably low.     

利用水泥窑焚烧垃圾时有害物质的生成条件与控制

进行了垃圾作水泥生产原料或燃料的分类，着重分析了水泥窑煅烧垃圾生产水泥时，有害排放物CO2，CO，SO2，NOx,重金属，HCl，二恶英和氟的产生过程和控制策略，在此基础上，推荐了一种烟气净化工艺流程，即采用向急冷塔中高压喷射碱液，并辅以袋式除尘器的方法不仅能避免二恶英的后期合成，还可有效降低烟气中SO2，HCl,F的含量。     

Cationic polymerization of ethylene oxide with Maghnite‐H as a clay catalyst in the presence of ethylene glycol

The activated‐monomer cationic ring‐opening polymerization of ethylene oxide, initiated with ethylene glycol and using an acid‐exchanged montmorillonite clay called Maghnite‐H⁺ as an effective catalyst, was carried out to obtain the corresponding homopolymers with narrow polydispersity ratios. The molecular weights of the obtained polymers were controlled with the feed ratio of the monomer to the initiator. The effects of the amount of the catalyst and time on the polymerization yield and viscosity of the polymers were studied. The structure was confirmed with proton nuclear magnetic resonance and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of chemically modified waste rubber powder as a filler in natural rubber vulcanizates

Waste rubber powder (RP) was subjected to chemical modification by using different concentrations of oxidizing agents such as nitric acid and 30% hydrogen peroxide solution. This treatment leads to introducing some functional groups onto the surface of RP. The chemically modified RP was incorporated in natural rubber mixes either alone or in combination with carbon black (HAF). The physicomechanical properties of NR vulcanizates obtained were studied and compared to NR vulcanizates filled with untreated RP. It was found that the chemically modified RP improves tensile strength and aging resistance of NR vulcanizates compared with untreated RP. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 30–36, 2004     

Characterization of a chromium-rich tannery waste and its potential use in ceramics

Leather industries which promote hide stabilization by the conventional chrome-tanning process are a major source of pollution because of the resultant chromium-rich wastes. In this work, an extensive characterization of such a chromium-rich waste sludge is presented, regarding its chemical composition (XRF), crystalline phase contents (XRD), organic carbon content (TOC), thermal behavior by thermogravimetry (TG) and differential scanning calorimetry (DSC), as well as its stability under chemical attack (the concentration of important ions in the leachates being determined by capillary electrophoresis) and when submitted to temperatures as high as 1100 °C, in air. The material showed the tendency to produce some undesirable, and previously non-detected hexavalent chromium when exposed to high temperatures, but after washing off the soluble salts and the elimination of the organic matter by firing, the resultant material was succesfully tested as a ceramic pigment in a conventional glaze composition usually employed in the ceramic tile industry.     

把节能当作一种资源去开发：空压机余热回收的成功应用

介绍了空气压缩系统的运行和耗能情况,针对其中存在的节能空间进行了改造,分析了压缩机的余热利用产生的经济效益。     

Application of grits waste as a renewable carbonate material in manufacturing wall tiles

This work focuses on the reuse of grits waste, from cellulose industry, as a raw material to replace traditional carbonate material in ceramic wall tiles. Wall tile formulations bearing up to 15?wt% of the grits waste were prepared for replacement of calcareous. The tile manufacturing route consisted of dry powder granulation, uniaxial pressing, and firing at temperatures ranging from 1100?°C to 1180?°C by using a fast-firing cycle. The wall tile specimens were tested to determine their physical and mechanical properties (linear shrinkage, water absorption, apparent porosity, apparent density, breaking strength, and flexural strength). The firing behavior, phase transformations, and microstructure were evaluated by dilatometry, XRD, and SEM. The results showed that the fired wall tile specimens are composed of anorthite and quartz, as major mineral phases, and mullite as a minor phase. It was found that the grits waste had a positive influence on the properties and microstructure of the wall tile specimens. The results also revealed that the grits waste from cellulose industry could be used as a total replacement of traditional calcareous material in wall tile formulations.     

城市垃圾焚烧飞灰处理技术及其在水泥生产中资源化利用

分析了城市垃圾处理技术的现状和发展趋势;介绍了城市垃圾焚烧飞灰处理技术的发展和资源化利用的紧迫性;阐述了水泥生产中资源化利用垃圾焚烧飞灰的可行性和前景;回顾了国内外水泥生产协同处理固体废物技术的发展历程,并提出了目前亟需解决的一些关键技术。在广泛研究的基础上,明确指出了水泥生产中资源化利用垃圾焚烧飞灰是实现焚烧飞灰资源化利用和无害化处理的重要途径。     

Changes in the CEC of a soil smectite–kaolinite clay fraction as induced by structural iron reduction and iron coatings dissolution

Studies of the effects of changes in iron (Fe) redox status on cation exchange capacity (CEC) and other physical and chemical properties of clays have typically focused on purified clays or clay fractions, but little attention has been given to systems with mixed mineralogy, which is more typical of natural soils. The objective of this study was to measure and establish any correlation between changes in CEC and Fe mineralogy that occurs in a mixed-mineral clay system undergoing chemical reduction. The clay fraction (SE1089) of a soil containing a mixture of smectite, kaolinite, and Fe oxide was investigated using variable-temperature Mössbauer spectroscopy, chemical analyses, and reductive dissolution in CBD media. This study revealed that in the unreduced clay fraction half of the total Fe was structural iron (Fe_Str) in the smectite and half was in goethite. The goethite particles were estimated to be 9 nm in mean crystal diameter (MCD) and to contain 9% Al substituted isomorphously for Fe.An evolution of the different Fe pools and changes in CEC of the mixture were observed. The CEC of SE1089 smectite fraction sharply increased upon reduction, similar to the SWa-1 reference clay, even though the Fe_Str content of SE1089 is much less. Results revealed a correlation of the increase in CEC with Fe_Str reduction and oxide dissolution, giving a direct connection between the total coating content and the rate of dissolution. For this reason, dissolution kinetics appears to be a key factor in understanding the control of CEC by iron coated material. In particular, in natural media governed by bacterial activity, different dissolution kinetics are expected.     

Gasification of high moisture rubber woodchip with rubber waste in a bubbling fluidized bed

This study investigated co-gasification of high moisture rubber woodchip (RW) with shredded rubber waste (SR) as an alternative to pre-drying of woodchip and effective utilisation of wastes. The shredded rubber waste was added into the rubber woodchip having originally 27% moisture content at 10 and 20 wt.% based on the dry weight of rubber woodchip. The mixtures were gasified with air in the 100 kWth bubbling fluidized bed gasifier at various equivalence ratios (ER). Operated at the same ER, the SR addition was found to raise the gasification temperature, e.g. an increase from 700 °C without SR addition by ~ 70°C with 20% SR addition. The heating value of synthesis gas generally increased with increasing % SR addition and with decreasing ER. Due to the resulting higher gasification temperature obtained from gasification with SR addition, it is possible to operate gasification at lower ER compared to the case without SR addition leading to the higher CO/CO₂ production ratio. Both ER and SR addition gave a positive effect on the carbon conversion efficiency; while the gasification efficiency was more influenced by the fuel chemistry. The amount and heating value of fly ash were slightly decreased in all mixtures with increasing ER, while increasing the SR addition ratio resulted in the higher fly ash due to the high ash originally present in the rubber waste. Overall, the performance and products from co-gasification were significantly improved compared to those from gasification using the high moisture woodchip alone and almost as good as that obtained when using low moisture woodchip. This implies the direct usability of high moisture rubber woodchip by adding shredded rubber waste without the need of pre-drying and moreover an improvement of the gasification performance and products.     

Potential for use of crushed waste calcined-clay brick as a supplementary cementitious material in Brazil

The Brazilian ceramic industry generates large amounts of calcined-clay waste. This paper examines the factors that influence its potential for use as a partial replacement of Portland cement. Superplasticized mortars of equal workability containing ground crushed waste calcined-clay brick (GCWCCB) in the proportions of 10, 20, 30 and 40% as a cement replacement were analyzed through mechanical tests, pore structure characterization and durability tests. The results indicated the optimal percentages of substitution lies between 10% to 20%. The potential reduction of CO₂ emissions could be as high as 10% of current Brazilian cement industry emissions if this approach were to be fully implemented, and it could be eligible for “Clean Development Mechanism” credits under Kyoto protocol.