关于提高煤矸石砖质量的调查

<正> 我国煤矿每年排弃的矸石量约占原煤产量的20～30%,数量很大。用煤矸石制砖,每年可以“吃掉”60～100万 t 煤矸石,而且减少了环境污染,使大量的耕地免遭破坏。同时,还可为近万名待业青年提供就业场所。所以,用煤矸石制砖是一项一举数得、利国利民、造福子孙后代的事业。应该受到更广泛的重视,使之更迅速地发展。东煤公司现有煤矸石砖厂67座,年产砖6～7亿块,窑型齐全,机械化程度较高。这些砖厂为东煤公司的生产建设做出了一定的贡献。     

我国煤Gan石制砖的现状与发展

阐述了我国煤Gan石制砖的现状及制砖工艺和设备方面存在的问题，指出了煤Gan石制砖在原料的选择、产品品种、生产工艺等方面的发展趋势，建立煤Gan石砖厂应采用新一人代的制砖设备及人工干燥和隧道窑焙烧等先进工艺，从而达到优质、高效、低耗。     

利用煤矸石生产劈开砖的研究

本文利用煤矸石等原料进行劈开砖试验。通过对原料进行测试、分析，拟定配方进行试验。经过多次试验后，最终取得了比较满意的结果。     

山西煤矸石发电制砖效益好

把煤矸石粉碎制成砖坯，再用传输带把砖坯送入砖炉，不用燃料，可自燃的煤矸石砖坯引燃后迅速生成建筑用砖，自燃过程的热能又替代了煤矿要用的燃煤锅炉。一条高科技的生产线就这样实现了变废为宝。     

华丰煤矿煤矸石砖年生产能力达1．1亿块

新汶矿业集团公司华丰煤矿6000万块煤矸石砖生产线二期工程已竣工。至此，该矿煤矸石砖年生产能力达到1．1亿块。今年，该矿抓住国家推广新型环保墙材和该矿新型煤矸石墙材旺销的有利时机，建设了煤矸石砖生产线二期工程。工程自今年3月1日破土动工，历时3个半月建成投产，创出全国同行业规模生产线建设最短周期。工程采用国内先进的煤矸石一次码烧、真空硬塑成型煤矸石制砖自动化生产工艺和制砖设备，     

利用煤矸石生产内燃砖的探索

利用工业废料生产普通砖或砌块等新型墙体材料,是我国墙体材料改革的发展趋势之一。这一举措不仅使工业废料得到了综合利用,也保护环境;而且给生产企业带来了巨大的经济效益。符合节能减排、可持续发展战略。本文就武陵地区煤矸石的综合利用——生产煤矸石内燃砖做了生产性试验探索。     

煤矸石制备多孔保温砖工艺优化及烧结机理探讨

为响应建筑节能与绿色建筑发展的号召,以煤矸石固体废物为主要原料,通过焙烤工艺制作保温砖,从而减少环境污染.针对保温砖目前存在的问题,提出了工艺优化方案,并对优化后的保温砖性能进行了测试.结果表明,采用新工艺制作的保温砖抗压强度和保温性能均满足建筑要求.     

利用煤矸石制砖的环境影响分析

以晋城康厦建材有限公司的煤矸石砖生产线为例,探讨了利用煤矸石制砖可能造成的环境影响,并针对采取的防治措施进行了评价,肯定了此工艺的可行性。     

全煤矸石砖泛霜的研究

通过实践经验,提出了通过调整窑炉的烧结制度来解决煤矸石砖泛霜问题的思路。     

煤矸石烧结普通砖砌体质量事故分析及处理

煤矸石烧结普通砖是煤矸石综合利用的一条理想途径,是国家大力推广的新型节能建材,是煤矿将煤矸石变废为宝,节约耕地的有效措施.但是,在实施过程中,个别砖厂由于质量控制不严,让不合格的砖出厂,造成工程上的重大质量事故.为减少经济损失.本文对已经用在某工程上的砖提出了合理处理建议.     

黑箱模型方法及其在耐火材料工艺中的运用

介绍了黑箱的概念,叙述了建模的条件,讨论了控制的方法;并以高纯硅砖为例,通过分析问题、设计试验、建立模型、进行优化,研制出了高纯度、低气孔率、低真密度和高强度硅砖。最后,探讨了利用信息技术提升耐火材料工艺的问题。     

抛光砖污泥在广场砖中的再利用研究

本文以陶瓷工厂抛光砖污泥、黑泥、章丘土、临朐长石、沂水长石以及秦庄长石为原料,制备了六组广场砖样品,其污泥含量分别为10%、20%、30%、40%、50%和100%。然后对样品进行各种物理性能测试和研究。结果表明:当抛光砖污泥的含量<30%时,可以用于广场砖的生产,且污泥含量越低产品的性能越好。     

The "Direct Bond" in Magnesia Chromite and Magnesia Spinel Refractories

The microstructures of several commercial refractory bricks have been characterized using scanning and transmission electron microscopy. The "direct bond" is shown to be direct at the level of resolution attainable (∼0.3 nm), and a significant number of such direct contacts occur between non-silicate phases in the microstructures of magnesia-chromite bricks. However, attempts to examine the direct bond in magnesia-spinel bricks were unsuccessful due to nonuniform ion thinning of TEM specimens.     

The steeple spire of the Parma Cathedral: An analysis of the glazed bricks and mortars

In October 2009, a terrible lightning struck the steeple spire of the Parma Cathedral, causing a fire. The fire-fighting operation made possible the discovery of the original spire ceiling made up by dichromatic glazed bricks, white and black, dating from the 14th century. Original materials presented a relevant decay, both for the high temperatures reached during the fire and for lack of maintenance. The research presents the first study of glazed bricks of the 14th century in Po Valley (Italy) with the purpose of collect chemical, mineralogical and petrographic data on the dichromatic glazed bricks. Brick samples with different kind of glazes and mortars exposed at different condition of fire were analyzed. The following techniques were used in the study: X-ray powder diffraction, optical microscopy, scanning electron microscopy analysis, inductively coupled plasma atomic emission spectroscopy and Raman spectroscopy. Glazes, applied on to Ca-rich paste, have a high lead content (41–57 wt%), with an high amount of tin (19–24 wt%) for the white opacified glazes and manganese (about 4.0 wt%) for the black ones. Typological and historical analysis allowed us to define the production technique of bricks and glazes. Mortars are mainly composed of lime binder and carbonate aggregate.     

纳米颗粒改性酚醛树脂用于镁碳砖结合剂的研究

利用纳米粒子对镁碳砖生产用酚醛树脂粘合剂进行了改性。改性树脂常规指标符合镁碳砖结合剂的要求。FE-SEM照片可以看到球形和近球形的纳米颗粒,分散均匀且基本无团聚。制砖实验结果表明,以改性树脂为结合剂能有效地减小显气孔率,增大体积密度且明显提高砖的压缩强度。特别是以TEOS(正硅酸乙酯)和纳米炭黑改性酚醛树脂为结合剂的镁碳砖,经200℃/12h热处理后的常温压缩强度分别提高了38.5%和30.4%,达到了43.94MPa和41.35MPa。砖坯的理化性能检测表明,随处理温度的升高,压缩强度和体积密度越来越小,显气孔率越来越大,200~1100℃各指标变化显著,1100~1550℃各指标没有显著变化,但呈变差趋势。     

Kaolin refractories for the lining of the iron notch of a 5000-m3 blast furnace

Conclusions The formation of the black core in large kaolin bricks during the firing process is caused mainly by the reducing medium which develops in the central part of these high-density refractories, graphitizes the carbon, and converts some of the high-valence iron and titanium oxides to low-valence oxides. The principal sources of the reducing medium inside the brick are the spent sulfite liquor and the sulfur- and carbon-containing impurities of the starting material. The likelihood of a black core being formed increases with the density of the green product and the rate at which the kiln temperature is raised.The properties of the light-colored outer and black inner zones are dissimilar so that cracks are formed during heating and cooling.In a joint project with the Zaporozhe Refractories Plant the Ukrainian Scientific-Research Institute for Refractories developed a method of producing high-density kaolin brick without black core.The method was used to produce about 200 tons of bricks measuring 345×150×150 mm and 230×150 ×150 mm for the lining of the iron notches of the 5000-m³ No. 9 blast furnace of the Krivoi Rog Metallurgical Plant.Translated from Ogneupory, No. 7, pp. 16–22, July, 1976.     

Facile and scalable synthesis of uniform MgO/Carbon Black nano-admixture for microstructural and mechanical property improvement of magnesia-carbon refractory bricks

Facile and scalable synthesis method of MgO/Carbon Black nano-admixture as an additive for MgO/C refractory bricks has been developed via simple precipitation method. The main idea of the present work lies on the precipitation of magnesium hydroxide in well dispersed/stabilized carbon black nanoparticle suspension resulting in Mg(OH)₂/CB nano-admixture preparation. Furthermore, applying such colloidal suspension of CBs prevent the sever agglomeration of Mg-containing precipitate and make simple precipitation method as a reliable synthesis method of nano-structured MgO. Finally, different analytical methods including X-ray diffractometer, Scanning electron microscopy, Cold crushing strength and physical properties measurement have been utilized to study the effect of such nano-admixture on the microstructural and mechanical properties of typical MgO/C refractory bricks.     

"In-situ Recycling" :Monolithic Ladle Repair with Shotcreting

The service life of refractories in ladle walls is limited by corrosion,abrasion,thermal shock and structural spalling mechanisms. When the ladle is lined with bricks they typically need to be completely removed after a certain number of heats to be replaced by new bricks of the same size as the original bricks. Not so for monolithic ladle linings. At the end of their service life the remains of the castable can almost completely be recycled as they can in fact stay in place. Only the worn-out part of the lining has to be replaced by a new castable. 20%-50% of the initial ladle lining can be recycled "insitu". The installation can efficiently be done by shotcreting technics. But it requires a castable that resists slag penetration very well. Castables based on a calcium magnesium aluminate bond provide the required penetration resistance. Pumping and shotcreting is very well adapted for repairs of blast furnace shafts,torpedo cars,hot metal and steel ladle linings[1]. However,very little is published about how a good pumping and shotcreting performance can be achieved when the installation has to be done under extreme weather conditions. At high ambient temperature the challenge is to ensure a good pumping result without early castable stiffening. Blockage of the pump would be the consequence. At low ambient temperature the difficulty is to de-activate the highly efficient deflocculant fast enough with a gelling agent added intothe wet mix at the nozzle to prevent the gunned material slipping off the wall. This paper studies strategies how to achieve good installed properties even at extreme ambient temperatures. The interactions between deflocculants,retarders,gelling agents,and calcium magnesium aluminate binder as a function of temperature are studied for an alumina- spinel ladle castable. Beside a new gelling agent for this castable type also a special stabilizer to reduce the temperature sensitivity has been investigated. It will be highlighted how the use of the new calcium magnesium aluminate binder in ladle castables and shotcretes maximises their service life and minimises material consumption.     

Thermal conductivity of MgO-C refractory ceramics: Effects of pyrolytic liquid and pyrolytic carbon black obtained from waste tire

In the present study, thermal conductivity and mechanical properties of MgO-C refractory ceramic bricks were investigated. Pyrolytic liquid and pyrolytic carbon black obtained from pyrolysis of waste tires were used as a resin and carbon source, respectively. The pyrolysis of the tires was conducted in a fixed bed reactor at the temperature of 500?°C with a 15?°C/min heating rate under nitrogen flow (0.5?lt/min). Before using in MgO-C refractory ceramic blends, pyrolytic products were purified with the acidic extraction methods which resulted in 61and 66?wt%. decreases in sulfur and ash contents in pyrolytic carbon, respectively. After this treatment of pyrolytic liquid, the sulfur content was reduced by 24?wt%. Eight different blends of MgO-C refractory ceramics consisting of different pyrolytic product contents were prepared, pressed, and tempered at 250?°C, and then characterized in terms of porosity, thermal conductivity, and density. The mechanical behavior of the samples was tested using a three-point bending test. Archimedes test was employed to determine the porosity and density. Surface properties of the bricks were analyzed by scanning electron microscopy (SEM). The obtained results were compared with a reference consisting of graphite and resin. The results revealed that mechanical and thermal properties of the developed bricks were highly sensitive to the porosity and the carbon source as well as the type of binder.     

Slag Resistance of Refractories for Direct Reduction of Laterite Nickel Ores in Rotary Kilns

Aiming at prolonging the service life of refractories for direct reduction of laterite nickel ores in rotary kilns, the slag resistance of ten materials(corundum bricks, chrome corundum bricks, silicon nitride bonded silicon carbide bricks, high alumina silicon carbide bricks, high alumina bricks, magnesia chrome bricks, magnesium aluminate spinel bricks, spinel chrome corundum bricks, chrome corundum castables and magnesia alumina chrome composite spinel bricks) was evaluated by rotary slag tests, which simulate the service conditions in rotary kilns. The corroded residual bricks were analyzed by SEM and EDS. The results show that the magnesia alumina chrome composite spinel brick possesses the advantages of magnesium aluminate spinel bricks and chrome corundum bricks; MgO-rich spinel can absorb the penetrated ferric oxide, and forms a dense zeylanite layer, which prevents the penetration of the molten laterite nickel ores; therefore, it is an ideal lining of rotary kilns for direct reduction of laterite nickel ores.