高速钢固体废物的再生研究.pdf

这是一个较好的工艺条件; 试验 A2B2C1 反应温度 50 ℃、 反应时间 50 min、pH2 是可能好的工艺条件, 不在 9 次 试验 中, 因 此补 充试 验 A2B2C1。 试验 A2B2C1的结果 ηCd2100, η Cd2 ηNi2 40 确实比 试验 A2B3C1的 结果 ηCd2 100, ηCd2 ηNi2 21. 3 高 ,说明 A2B2C1的工艺条件是较好的 ,即 CdO、 NiO 在50 ℃,pH 2 的 H2SO4溶液中 50 min 内,Cd 2 的浸出率达到 100,Ni 2的浸出率只有 2. 5,因此 A2B2C1条件下可实现镉的优先浸出。 5 结论 1 热力学和动力学分析表明, 将废镉镍电池中 的Cd 、 Ni 转化成氧化物 ,控制温度 、 酸度和时间,能使 Cd 优先浸出。 2 通过正交试验得出 Cd 优先浸出的适宜工艺 条件为 50 ℃、 pH 2 的硫酸溶液中浸 50 min,在此工 艺条件下, 镉能全部浸出 ,而镍的浸出率只有 2. 5。 参考文献 1 杨显万等. 高温水溶液热力学数据计算手册. 北京 冶金工业出版 社, 1983. 2 李洪桂. 浸出过程的动力学基础. 稀有金属与硬质合金, 1992. 4 30. 作者通讯处 王敏 100044 北京建筑工程学院城建系环境教研室 2004- 09-28 收稿 高速钢固体废物的再生研究 夏文堂 温俊杰 陈 勇 曹道锦 中南大学冶金科学与工程学院, 湖南 长沙 410083 摘要 采用电热法回收高速钢固体磨屑废物中的合金并生产再生合金并对冶炼再生合金产品的工艺及影响产品质量 的因素进行了研究。 首先对高速钢磨屑进行预处理, 去除杂质, 得到精磨屑。 冶炼采用的多元碱性渣系解决了炉渣的 流动性问题; 复合还原剂为理论配入量的99～ 100。 研究结果表明, W 和Mo 回收率大于 96, Cr 及V 回收率不低 于91。 冶炼回收的再生合金产品满足了炼钢的要求, 并做到了二次资源的再生利用, 减少了环境污染, 符合国家产 业政策, 社会效益明显。 关键词 高速钢 固体废物 磨屑 再生合金产品 电热法 1 概述 高速钢磨屑是高速钢钢材和刀具加工过程中产 生的一种工业固体废料 , 其总量占钢材的 0. 5～ 5、 是刀具所用材料的 5～ 15。由于其杂质含 量高且细小 80～ 120 目 , 并且由于冷却介质的作用 使磨屑易于生锈并结块, 无法直接利用 , 一般被作为 工业垃圾废弃, 从而造成了 W、 Mo 、 Cr、 V 等稀有合金 的浪费,且污染了环境。由于高速钢磨屑中所含有的 W、 Mo、Cr 、 V 是贵重合金元素, 这些合金元素加入钢 中主要与碳结合形成碳化物, 对细化钢的晶粒 ,提高 钢的硬度、红硬性和耐磨性有重要作用 , 是特钢生产 中不可缺少的合金元素, 因此具有很高的再生利用 价值 。 通常情况下 ,废弃金属的再生利用 ,比矿石冶炼 合金更为经济 [ 1] 。因为矿石冶炼原生合金所需原料 因品位较低 ,成分相对复杂 ,需经过一系列复杂的工 艺,经富集后才能达到冶炼合金要求 。同时生产原生 合金时还需消耗大量的燃料及其它原料 ,因而生产原 生合金的费用较高, 且生产工艺流程长, 工序多,工艺 复杂 ,生产过程中的废水 、 废气 、 废渣导致环境污染严 重。作为二次资源的高速钢磨屑的开发利用 ,不但可 以降低特钢生产成本, 而且有利于节省资源 ,减少环 境污染,丰富特殊钢炉料市场 。对于高速钢磨屑的再 生利用国外的开发利用比我国起步要早, 且起点高。 如美国对于高速钢磨屑的回收利用采取的是化学处 理 [ 2,3] 方法来回收其中的 W、 Mo 等合金元素; 日本及 俄罗斯采取了焙烧还原及粉末冶金工艺技术 [ 4,5] , 充 分利用了磨屑废物 。而采用电热法回收高速钢固体 58 环 境 工 程 2005年 2 月第23 卷第1 期 磨屑废物中的合金元素还未见报道 。 2 高速钢磨屑的预处理及冶炼 高速钢磨屑细小 ,由于冷却介质的作用易于生锈 且含有一定的油污 ,P 、 S 杂质含量高, 而且其中还含 有砂轮刚玉 ,要达到再生的目的, 必须经除油去锈及 杂质等工艺。对于油污的处理 ,通常采用高温水中加 入碱的办法, 而对于锈的处理一般采用酸处理的工 艺。这些措施不仅可以去除油污和锈蚀 ,而且还去掉 了部分P 、 S 杂质。 该冶炼采用了电渣炉的优点, 通过把电能转化为 热能 ,使渣液过热,在加料过程中通过还原剂 ,还原高 速钢磨屑中的氧化物 ,达到除去P 、 S 杂质及再生高速 钢磨屑的效果。 3 试验设备及试验原料 3. 1 试验设备 表1 为用于本试验的设备。 表 1 试验设备 设备名称设备型号测试范围数量用途 标准样筛 6、12、24、28、45、 55、 75、 100、150、200 目 0 . 057～ 3 . 5 mm 1套测定粒度 普通筛自制 1 . 5 mm ～ 5 mm 1台筛选磨屑 烘干炉自制1台烘干磨屑 磁选机PC-3 60C1台磨屑磁选 冶炼炉自制100 kVA1台冶炼 衡器 AGT-10 型 TGT-500型 0～ 10 kg 0～ 500 kg 1台 1台 称量 搅拌器自制1台高速钢磨屑预处理 破碎机2台破碎 3. 2 试验原料 高速钢磨屑 高速钢磨屑为 W9Mo3Cr4V 及 W6Mo5Cr4V2 高速钢混合料 。 复合还原剂 一种特殊的还原剂, 无氧化 。 石灰 CaO 选用一级石灰。 萤石 CaF2 选用特一级萤石。 4 高速钢磨屑再生合金的试验工艺及化学成分结果 4. 1 试验的工艺流程 本试验的工艺流程见图 1。 图 1 试验工艺流程 4. 2 化学成分结果 高速钢磨屑再生合金的化学成分主要由高速钢 磨屑成分炉料组分和冶炼工艺参数控制 ,回收再生产 品的化学成分见表 2。 表 2 高速钢磨屑再生合金产品的化学成分 炉号CSiMnPSWMoCrV 0160211 0 . 90 0 . 53 0 . 330 . 0270 . 0317. 91 3. 82 3. 981 . 51 0160212 1 . 17 0 . 60 0 . 320 . 0210 . 0217. 85 3. 90 4. 001 . 53 0160311 1 . 28 0 . 59 0 . 340 . 0290 . 0408. 05 3. 79 3. 921 . 48 0160312 1 . 17 0 . 65 0 . 320 . 0350 . 0367. 92 3. 85 4. 121 . 49 0160411 1 . 05 0 . 61 0 . 340 . 0290 . 0317. 81 3. 80 3. 891 . 50 0160412 1 . 19 0 . 58 0 . 320 . 0320 . 0238. 11 4. 00 4. 201 . 50 0160511 1 . 19 0 . 60 0 . 320 . 0270 . 0438. 14 3. 81 3. 991 . 47 0160512 1 . 10 0 . 53 0 . 300 . 0280 . 0277. 85 3. 91 3. 951 . 51 根据试验数据, 用电硅热法回收的再生合金产品 其化学成分比较稳定, 合金元素成分波动小 ,对冶炼 高速钢及其它合金钢非常有利 。 5 高速钢磨屑再生高速钢合金产品的工艺参数及影 响因素 高速钢磨屑再生是一个复杂的物理化学过程。 影响技术经济指标的因素很多 , 经多次试验 ,我们认 为主要取决于以下工艺参数。 5. 1 高速钢磨屑原料的影响 通常情况下,高速钢磨屑的含P 量约为0. 035, S 含量大于 0. 06,比高速工具钢中 P ≤ 0. 030,S ≤ 0. 030 超出许多 。为保证冶炼过程中的质量, 需对 高速钢磨屑进行预处理,预处理后的高速钢磨屑含 P 量一般小于 0. 031 , 而 S 含量在 0. 035左右, 为进 入电热炉冶炼保证了质量 。 5. 2 还原剂配入量的影响 炉料中还原剂的配入量是影响高速钢磨屑回收 技术及经济指标的重要因素之一,还原剂配入量系数 与W、 Mo 、 Cr 及 V 回收率的关系如图 2所示。 从所得试验数据所做的还原剂配入量系数与回 收率的关系图可知, 当还原剂量不足时,W、 Mo 、 Cr 和 V 的回收率相对较低 ,这是由于还原剂量不足以还原 高速钢磨屑中的合金氧化物; 当配入量系数太高时, 过剩的还原剂进入回收的产品中; 另一方面使得渣液 变稠, 不利于金属液滴的充分沉降, 造成合金回收率 下降 。配入还原剂系数与再生合金产品含硅量的关 系图 3,合适的还原剂配入量为99～ 102。 59 环 境 工 程 2005年 2 月第23 卷第1 期 图 2 还原剂配入量与合金回收率的关系 图 3 配入还原剂系数与再生合金产品含硅量的关系 5. 3 炉料组分的粒度影响 在冶炼回收条件相同的状况下 ,炉料组分的粒度 对冶炼过程中的冶金反应能否顺利进行起重要作用。 炉料组分越细, 则混合后便能在被还原氧化物和还原 剂的颗粒间造成良好的接触, 这种良好的接触可以增 加冶炼回收的反应速度, 使得还原剂得到充分利用; 炉料组分颗粒太粗, 则使还原剂在没有充分参与反应 的情况下而直接进入钢液中。但若还原剂太细,在混 料时极易飞跑, 装料过程中极易氧化而损失严重, 起 不到还原剂应有的作用。经试验和生产证明 ,炉料组 分的粒度以下列数值 见表 3 较为理想 。 表 3 炉料组分的粒度 炉料组分高速钢磨屑复合还原剂萤石石灰 粒度≥ 80 目≤5 mm≤5 mm≤ 5 mm 6 高速钢磨屑的合金元素回收率指标与其它回收工 艺的合金元素回收率指标的比较 表4 列出了国内外不同工艺的高速钢磨屑合金 元素回收率指标 [ 6,7] 。 表 4 高速钢磨屑合金元素回收率 回收工艺 回收率 WMoCrV 国外湿法冶金处理92. 689. 054 . 074. 6 国内真空炉处理92. 786. 752 . 635. 3 国内金属热法≥95. 0≥ 95. 045 . 020. 0 国内中频炉处理≥85. 0≥ 85. 0 本研究回收工艺≥96. 0≥ 96. 0≥91 . 0≥91. 0 7 结论 1 采用电热法回收的再生合金中,元素含量高, 化学成分稳定, 杂质含量低,经用户使用 ,完全满足高 速钢冶炼使用要求。 2 为保证具有较高的合金回收率指标 ,复合还 原剂的配入量为理论的 99～ 100 , 炉料组分的粒 度为高速钢磨屑 80 目, 复合还原剂、萤石 、石灰为 5 mm以下较佳 。 3 经近 400 t 高速钢磨屑的生产实践证明 ,用电 热法冶炼再生合金产品, 工艺技术可行 , 采用复合脱 氧剂和化渣操作 ,可保证 W、 Mo 、回收率 96,Cr、 V 回收率不低于 91。 参考文献 1 乐颂光等编著. 再生有色金属生产. 长沙 中南工业大学出版社, 1996 36～ 37. 2 美国专利, 专利号 3607236. 3 美国专利, 专利号 3649487. 4 Kiparisov, S. S; Padalko , O. V; Levinskij, Yu. W etal Resource -Saving and nature-protection potential of powder materials and technologies realization in the sphere of secondary resources recycling . Poroshkovaya Metallurgiya. 1993, 6 1～ 4. 5 Hara, Yoshiaki;Ishiwata , Natsuo Itaya , Hiroshi, etal. Smelting reduction process with a coke packed bed for steelmaking dust recycling . ISIJ International, 2000 40 , 3 231～ 237. 6 夏文堂, 王大宇. 高速钢磨屑再生利用展望. 中国资源综合利用, 2001. 3 17～ 18. 7 夏文堂, 夏建军, 王大宇. 高速钢磨屑再生合金基料的研究. 河北冶 金,2002. 4 , 17～ 18. 作者通讯处 夏文堂 410083 湖南长沙 中南大学冶金科学与工 程学院冶金分离科学与工程研究所 2004- 05-20 收稿 60 环 境 工 程 2005年 2 月第23 卷第1 期 ferrosilicon electric furnace. The investment analysis of recovering microsilicon fume was also conducted. Keywords ferrosilicon electric furnace, dedusting, recovery of microsilicon fume and benefit TECHNICALREOFDEVICEFORTREATINGPELLETINGTAILGASFROM PRODUCTIONOF COMPOSITE FERTILIZERYang Zhongmiao et al 41 Abstract It was analyzed that the problems of phosphoric acid -washing for primary treatment of pelleting tailgas from production of composite fertilizer, and that the causes of large amount of ammonia in the tailgas when water -washing is used for primary and secondary treatments. A technical scheme of using phosphoric acid -washing for secondary treatment is also proposed, whose operations show that the re is successful and using phosphoric acid-washing for secondary treatment is feasible. Keywords pelleting tailgas, ammonia, phosphoric acid and re EXPERIMENTAL STUDY ON FUSION AND PICK-UP BY SOAKING FOR FLY ASH IN MUNICIPAL SOLID WASTE MSWINCINERATIONZhong Zhaoping et al 43 Abstract It isdescribedthat the process of experimental study on the fusion at high temperature for fly ash in municipal solidwaste MSW incineration and the perance of the pick -up by soaking for the fusing dregs. The experiment of fusion is operating in Marver stove, and the experiment of pick -up by soaking is operating in distilledwater, acetic acid,whose pH is4. 5, and sulphuric acid, whose pH is 3. The resultsof the experiments are as follows. The amount of the heavy metal Cd, Cr, Zn, Fe increases asthe time of fusion goeson, the amount separted out decreases obviously. By prolonging the time of fusion, the pollution of these metals can be reduced. Because the heavy metal Hg volatilizes easily, the time of fusion has little effects on its amount separated out. The amount separatedout of heavy metalZn, Cd etc. decreases obviously with its temperature of fusion increasing, so the pollution of these can be reduced by raising its temperature of fusion. The amount separated out of the heavy metal Cr increases with the rising of the solvent s pH,while the amount separated out of Cd, Pb, Zn in acetic acidis the greatest, and water is the smallest. For these heavy metals and acetic acid having complex reactions, so its amount separated out is the greatest. Keywords fusion, pick-up by soaking, MSW incineration and cinder STUDY ONTECHNOLOGY OF PLASTIC SEPARATING AND RECYCLING FROM MSW Lǜ Chuanyi et al 45 Abstract The component of MSW was analyzed, and the necessity of separating plastic and recycling plastic from the MSW wasexpatiated. The new processof separating plastic and recycling plastic from the MSW was brought forward. The motion parameters of separating plastic and the perance parameter of plastic boardwere given. The key techniques, such as crushing, enlacing, changing density and so onwere also solved. The technical inds of the fabricated boards can meet the requirements of building materials. Keywords MSW, plastic separating , changing density , recycling resource and plastic board TREATMENT OF NITROGEN OXIDE WITH SOIL FILTRATIONDu Jijun et al 48 Abstract The biological treatment of nitrogen oxide in waste gas by soil filtration was investigated. The study focused on the effect of soil, concentration, temperature and air velocity through reactor. The experiment result demonstrated that pollution caused by nitrogen oxide canbe controlled by soil filtration. The removal efficiency of nitrogen dioxide was above 90. Enrichment soil was better than poor soil as filtration medium. The removal efficiency was increasedwith increasing of concentration, when concentration higher than 2 mg m3, the removal efficiency was around 95. The increasing of temperature was of benefit to the removal efficiency. On the other hand, it also prolonged the operation time of soil filter. In the range of the experiment, the increasing of gas velocity in the reactor didn t decrease the removal efficiency of NOX. Keywords nitrogen oxide, soil filtration and biopurification DESIGNOFTHEINCINERATIONPLANTFORSOLIDWASTEFROMPUDONG INTERNATIONAL AIRPORTWang Yanming et al 51 Abstract It is introduced systematically that the incineration processfor the treatment of solidwaste from Pudong International Airport. And the process flow and design parameters including material balance and safety control theory have been detailed. Keywords solid waste from airport, incineration technique, material balance and process control PRIORITY LEACHING OF CAMIUM FROM SPENT CADMIUM -NICKEL BATTERIES Wang Min 56 Abstract Thermodynamics analysis and kinetics analysis of priority leaching of cadmium from spent Cd -Ni batteries have been carried out. The leaching conditions differ greatly between CdO andNiO, which was experimentally investigated. The results show that at 50 ℃ and pH2 of H2SO4solution in 50 min leaching, the leaching ratio of cadmium and nickel is 100 and 2. 5 respectively. Keywords spent cadmium -nickel batteries, thermodynamics, kinetics, cadmium and priority leaching RESEARCH ON RECOVERY OF ALLOYS FROM SOLID WASTE OF HIGH SPEED STEEL Xia Wentang et al 58 4 ENVIRONMENTAL ENGINEERING Vol. 23, No. 1,Feb. , 2005 Abstract The goalwas to recycle secondary alloys raw material from solid waste of high-speed-steel tool swarf by electrothermal process. The techniques and the factors affecting the quality of products were analyzed. For getting pure high-speed-steel tool grinding swarf, the pre - treatment was needed. The multi -alkaline slag could not only meet the need of high heat value, low oxidation andgoodfluidity , but also increase the recovery ratio of alloys andwipe out impurity. The compound reducing reagent was about 98～ 100 of its theoretical consumption. The results showed that the quality of the secondary alloy raw material recycled from waste solid of high -speed -steel tool could meet the need of steel -making. From which remarkable social and economic benefits are achieved. Keywords high speed steel, solid waste, grinding swarf, secondary alloy raw material and electrothermal process DETERMINATION OF TOTAL CHROMIUM INWASTE -WATERBY FLAME ATOMIC ABSOPTION SPECTROPHOTOMETRYYe Jun 61 Abstract A determination of total chromium in environmental samples by flame atomic absorption spectrophotometry was studied. The optimal analytical conditions were ascertained through different experimental conditions. Analytical precision and accuracy were also validated by means of analysis of standard samples and realistic samples. The experimental results showed that this was easy to operate. The anylytical efficiency was promoted, analytical precision and accuracy were good as well, so this could be applied and popularized. Keywords flame atomic absorption spectrophotometry, tatal chromium and determination MODIFIED LOGISTIC CURVEMODEL OF OVERALLUATION OFATMOSPHERE ENVIRONMENTAL QUALITYJinKaizheng 62 Abstract In order to test the grade criteria of atmosphere environmental quality , to resolve the non -uni problem of uation results of atmosphere environmental quality inds, and to raise the grade resolution of uation, a new model a modified Logistic curve model is suggested, whose atmosphere environmental quality grade is a real number. The calculation example shows that the scheme is practical, effective and general,which can be applied to uating other environmental quality. Keywords Atmosphere environemntal quality , overall uation and modified Logistic curve model APPRAISEMENT OF ENVIRONMENTAL QUALITY OF WATER BODIES BY TENDENCY WEIGHT POLLUTION INDEXYang Shijian et al 65 Abstract It was suggested that the of tendency weight pollution index should be used to assess the environmental quality of water bodies in the light of shortcomings of the of average pollution index, which was also compared to the average pollution index through examples. The results showed that the of tendency weight pollution index is accurate and convenient for the assessment on water bodies. Keywords environmental quality of water, uation, average pollution index and tendency weight pollution index DETERMINATION OFCOPPER,ZINC,LEADAND CADMIUM IN SOIL BY ATOMIC ABSORPTION SPECTROMETRYPan Haiyan et al 68 Abstract Through comparison of several counteraction systems, HNO3-HF -H2O2system is selected for Pb and Cd, while HNO3-HF -HClO4 system is selected for Cu and Zn. It has been showed through determinations of standard samples that the measured values are in the range of guaranteed oneswith a relative standard error of 2. 2～ 7. 2 and a recovery of 83～ 116for Pb and Cd; whereas a relative standard error of 2. 6～ 4. 5 and a recovery of 92～ 103 belong to Cu and Zn. Keywords atomic absorption spectrometry, soil, Cu, Zn, Pb and Cd ASSESSMENT OF WORKING ENVIRONMENT AMENITY BASED ON GREY RELEVANCY ANALYSISZhang Dongfang et al 70 Abstract In working environment amenity assessment, there are lots of influencing factor with different attributes. For the purpose of reflecting the attributes in the assessment and avoiding the trouble of distributing weight to every index, which is difficult generally, according to t