共查询到20条相似文献,搜索用时 171 毫秒
1.
研究了铸造湿型砂与树脂砂混合废砂的再生机制,并对采用二次焙烧技术处理的铸造废砂性能进行了深入的分析。试验指出,再生砂的灼烧减量比新砂低75%,发气量比新砂低25%,强度高于新砂15%,能满足铸造企业在制芯或浇注中的使用要求,从而可实现铸造废砂的再生利用。 相似文献
2.
3.
文章针对铸造废砂治理途径多元化的发展趋势,提出了建立区域性铸造废砂处理中心的思路,以解决困扰铸造行业多年的铸造废砂治理问题.并根据设计建成的铸造废砂柔性处理系统为模式,介绍了铸造废砂处理中心的设计思路和要点. 相似文献
4.
研究了以铸造废砂为填料、废旧地膜为基体,制备复合材料的界面问题.用加热-振动的方法可有效地除去覆盖在铸造水玻璃废砂表面的大部分惰性膜;用偶联剂进行表面改性后,可在不同程度上提高铸造废砂-废旧地膜复合材料的强度.提出并验证了制备铸造砂-地膜复合材料的有关工艺参数. 相似文献
5.
6.
铸造废砂再生处理与节能技术的应用 总被引:8,自引:2,他引:6
在铸造连续生产过程中,芯砂不断地混入型砂中,循环总量增加的部分只有经过再生处理代替新砂用于制芯,才能实现系统的封闭循环.废砂再生示范工程通过机械与适温焙烧等节能处理工艺,消除较高的需酸值和粘结剂间的相溶性,使混合废砂经有效处理后,成为具有了焙烧砂的优良特性,能达到优于新砂用于冷、热、覆膜砂制芯的目的,成为高品质再生资源.为大批量湿型砂生产的铸造废砂再生的全面实现创造条件. 相似文献
7.
随着铸造业的发展,铸造废砂排放日益增多,现有堆存处理不仅占用大量土地,还带来了严重的环境污染问题。本文从铸造废砂行业发展背景、资源化利用途径及其存在的问题入手,对宁波市铸造废砂的现状进行分析,针对铸造废砂排放量巨大、成分复杂、资源化利用低及监管效能低下等特点提出相应的发展建议,即:通过“强链、延链与补链”方式,建立多产业协同的铸造废砂循环利用系统,使“绿色+”成为新的经济增长点;结合“数字赋能”发展趋势,搭建铸造废砂数据库和信息共享服务系统,提高监管效能并服务产业,全链条提升废砂资源化利用率。 相似文献
8.
9.
10.
王兆雪勾东东韩小问刘晓娟苑博贾犇 《中国铸造装备与技术》2022,(6):104-107
沧州地区铸造产业废砂资源化利用主要通过废砂焙烧再生完成,但再生砂焙烧法会产生大量粉尘和有机废气,对企业周边生态环境产生一定影响。主要探讨焙烧法再生砂废气、固体废物和噪声等“三废”治理措施,并进一步提出优化的污染控制措施。 相似文献
11.
为了获得高性能PVA纤维增强水泥基复合材料的制备方法,研究了砂的颗粒级配、水胶比和粉煤灰掺量对高延性纤维增强水泥基复合材料(Engineered Cementitious Composites,ECC)的弯曲性能、抗压、抗折强度及开裂模式的影响。结果表明:随着砂的细度模数降低,ECC的跨中挠度增大,早期强度提高,但后期强度变化不明显。随着水胶比的增大,ECC的初始开裂荷载降低,跨中挠度增大,平均裂缝宽度增加。0.25水胶比的ECC的抗压强度可以满足高强度等级的要求。0.35水胶比的抗压强度可以满足对普通强度等级的要求。随着粉煤灰掺量的增加,ECC的初始开裂荷载降低、抗折和抗压强度逐渐降低,ECC的跨中挠度提高,平均裂缝宽度变小。在水胶比一定的条件下,采用细砂,适当增加粉煤灰掺量有助于提高ECC的韧性和延性。 相似文献
12.
对比研究了普通一次微波硬化、有机酯硬化、有机酯-微波复合硬化三种水玻璃砂硬化工艺的性能.结果表明,与普通一次微波加热硬化相比,有机酯-微波加热复合硬化工艺可使砂型在微波加热阶段不带模具加热,当有机酯的加入量为水玻璃质量的1.5%时,恒湿瓶中4h存放强度较普通一次微波加热硬化提高了70%;较之于有机酯硬化工艺,有机酯-微波加热复合硬化工艺的水玻璃加入量少、硬化速度快、硬化强度高.进一步系统研究了其他工艺参数(微波加热功率和时间)对有机酯-微波加热复合硬化水玻璃砂型存放强度的影响,并通过扫描电镜观察分析了该工艺下的砂样粘结桥微观结构和硬化机理. 相似文献
13.
《中国铸造》2016,(6):427-432
The paper presents the research results of using an innovative method to reclaim the waste moulding sands containing water glass. Two of the examined processes are connected with “dry” or “wet” activation of inorganic binder in waste moulding sand mixtures physicaly hardened by microwave radiation. The sand mixtures consisting of high-silica sand and water-glass with average molar module 2.5, were subjected to the folowing cyclical process: mixing the components, compacting, microwave heating, cooling-down, thermaly loading the mould to 800 °C, cooling-down to ambient temperature, and knocking-out. After being knocked-out, the waste moulding sands were subjected to either dry or wet activation of the binder. To activate thermaly treated inorganic binder, each of the examined processes employed the surface phenomenon usualy associated to mechanical reclamation. The study also covered possible use of some elements of wet reclamation to rehydrate waste binder. To evaluate the effectiveness of the two proposed methods of waste binder activation, selected strength and technological parameters were measured. After each subsequent processing cycle, the permeability, tensile strength and bending strength were determined. In addition, the surface of activated sand grains was examined with a scanning electron microscope. Analysis of the results indicates that it is possible to re-activate the used binder such as sodium silicate, and to stabilize the strength parameters in both activation processes. Permeability of the refreshed moulding sands strongly depends on the surface condition of high-silica grains. The wet activation process by wetting and buffering knocked-out moulding sands in closed humid environment makes it possible to reduce the content of refreshing additive in water-glass. The moulding sands cyclicaly prepared in both processes do not require the addition of fresh high-silica sand. The relatively high quality achieved in the refreshed moulding sands alows them to be reused for manufacture of next moulds. Thus, the two proposed methods for cyclicaly processing used moulding sands containing sodium silicate, subject to microwave hardening, are suitable for economic and ecological circulation moulding mixtures. 相似文献
14.
典型方法和材料对水玻璃的改性效果与机制 总被引:1,自引:0,他引:1
研究比较了超声处理、纳米粉末改性、复合材料改性等水玻璃粘结剂改性方法及材料对水玻璃粘结剂的改性效果;分析了水玻璃的改性机制。试验结果表明,超声处理虽然提高了水玻璃砂的常温强度,却也恶化了溃散性;水玻璃经过纳米氧化物粉末改性后,适量纳米氧化物粉末可以在一定程度上改善水玻璃砂的溃散性,但常温强度却不能得到较大幅度的提高,作者开发的复合改性剂,既可提高水玻璃砂的常温强度,又可改善水玻璃砂的溃散性。借助XPS和SEM微观分析的方法,探讨了水玻璃粘结剂改性方法及材料对水玻璃粘结剂的改性机理。 相似文献
15.
铸造镁合金旋转喷吹除气的试验研究 总被引:9,自引:0,他引:9
研究了旋转喷吹技术在AZ91镁合金熔体除气净化处理上的应用。采用减压凝固法考察了旋转喷吹的除气净化工艺的净化效果,确定了最佳的除气时间。利用金相显微镜观察了除气前后合金的微观组织。对除气前后的合金,进行了金属型和低压砂型铸造试验浇注,并对其力学性能进行了测试和比较。研究结果表明,经过30min旋转喷吹除气处理后,能快速显著地降低镁合金中的含气量,AZ91合金金属型和低压砂型试样的力学性能都明显地得到提高,特别是合金的伸长率得到大幅度的提高。 相似文献
16.
李嘉荣董建民韩梅刘世忠 《金属学报》2023,(9):1201-1208
将标准热处理的试样分别采用粒径为150、124和100μm白刚玉砂在0.5 MPa压力下吹砂,研究吹砂对第二代单晶高温合金DD6表面完整性的影响;对未吹砂和粒径150μm吹砂试样分别进行760和980℃旋转弯曲高周疲劳性能测试,研究吹砂对DD6合金疲劳性能的影响。结果表明:吹砂会破坏单晶高温合金的表面完整性,使表面出现砂粒切削造成的不规则凹坑,改变表面形貌;砂粒粒径增加,表面粗糙度和显微硬度均增大;吹砂使大量位错在γ相通道中滑移,靠近表面区域位错密度较大;并且,大量位错剪切γ’相,形成反相畴界和层错;吹砂造成形变强化、引入残余应力;150μm、0.5 MPa吹砂对DD6合金760℃旋转弯曲疲劳性能基本无影响,但会降低合金980℃疲劳性能,对低应力幅区疲劳寿命影响较大,使疲劳强度下降约7.3%。缺口效应、氧化损伤、形变强化和残余压应力的耦合作用导致吹砂与不吹砂试样疲劳寿命产生差异。 相似文献
17.
吴剑 《中国铸造装备与技术》2020,(2):49-51
备受关注的铸造废旧砂再生处理是一个有工艺特性、相对独立复杂的工艺处理过程。针对中小规模铸造砂处理过程中的旧砂再生,其生产流程可以通过选择干法+热法+干法的综合处理方法,使大量废、旧砂复原、净化转化成优良品质的再生回用砂,或作为商品去替代原、新砂使用。如造型制芯砂、覆膜砂、壳型砂、V法铸造和消失模用砂等不同类型的铸造生产场合。 相似文献
18.
Young S. Cho 《NDT & E International》2003,36(4):229
Non-destructive testing is essential in the inspection of alteration, repair and new construction in construction industry. Researchers are exploring the performance of non-destructive testing method using spectral analysis of surface waves (SASW) in concrete structures. The method consists of the generation, measurement and processing of dispersive surface waves. In SASW test, the surface of the media under consideration is subject to an impact using, for example, a 12-mm steel ball, to generate surface wave energy at various frequencies. Two vertical accelerometer receivers detect the energy transmitted through the testing media. By recording signals in digitized form using a data acquisition system and processing them, surface wave velocity can be obtained using a dispersion curve. This study is to focus on understanding of the applicability and limitations of the SASW method in a high strength concrete. This study is also to characterize the material property of early age high strength concrete emphasizing compressive strength using non-destructive testing methods. Three high strength concrete slabs of 600, 850 and 1100 kg/cm2 compressive strengths were prepared together with cylinders from same batches. Cylinder tests were performed at the ages of 7, 14, 21 and 28 days after pouring concrete. Using the impact-echo method, the compression wave velocities were obtained based on different high strength concrete ages and compressive strengths. The equation to obtain the compressive strengths of high strength concrete has been developed using the obtained compression wave velocities (f′c=1.083Vp−3816.1143). Using the method, the equation has also been developed to obtain the compressive strengths of high strength concrete based on the surface wave velocities (f′c=0.253Vp+16.271). This study can be utilized in examining structural elements of high strength concrete structures and be applied in the integrity analysis of high strength concrete structures with a finite thickness. 相似文献
19.
20.
通过对酯硬化碱性酚醛树脂旧砂的模拟再生试验,分析了再生前后砂样的灼烧减量、发气量等性能的变化,以及对型砂强度的影响因素。结果表明:采用模拟再生工艺可使再生砂回收率达到95%左右;在再生砂中加入质量分数10%~20%的新砂,可明显提高再生砂的黏结强度,为更好运用酯硬化碱性酚醛树脂砂生产高强度钢种的铸件提供旧砂再生工艺方案。 相似文献