低含碳球团配加MgO试用研究

 为了获得高强度优质含碳球团,研究了不同MgO/SiO2比值和焙烧温度对煤粉添加量为6%的含碳球团性能的影响。研究表明：当含碳球团中的煤粉配比为6%、膨润土配比1.5%、MgO/SiO2一定时,随着焙烧温度（1200℃-1300℃）的升高,成品含碳球团的强度呈先增加后降低的趋势,且在1280℃时强度最大,焙烧温度过高,球团内部过熔化,产生大量孔洞,球团抗压强度较低,若焙烧温度过低,则球团未烧透,强度较差。     

不同碱度及含氧化镁球团矿实验研究

在实验室条件下 ,对不同碱度及不同氧化镁球团进行了试验研究。结果表明 :当碱度R≥ 1 0时 ,球团需高温焙烧才能满足生产要求 ;当碱度R <1 0时 ,其焙烧温度只需 12 5 0℃左右。对于含量MgO球团 ,随着MgO/SiO2 比值的增加 ,其焙烧温度显著提高 ,通过配加含硼矿物可降低含MgO球团的焙烧温度 ,即在 12 0 0～ 12 5 0℃之间就能满足球团生产工艺的要求。     

使用含硼添加剂降低球团矿焙烧温度的研究

在实验室条件下,对MgO质酸性球团配料分别加入2%的不同硼泥和贫硼镁铁矿,保持MgO/SiO_2比(0.5)不变,结果,球团矿焙烧温度降低50℃或更多,可达到1200℃左右。为使用竖炉焙烧MgO质酸性球团矿展示了乐观前景。     

关于含碳球团生产珠铁的硫含量控制试验研究

通过对以铁精粉、煤粉、石灰石及少量添加剂为主要原料的含碳球团进行还原试验,研究了碱度( CaO/SiO2)、反应时间、加热温度、添加剂及配碳比(C/O)等不同因素对于含碳球团还原熔分及珠铁中硫含量的影响,并分析了硫元素的分配情况.试验及分析结果表明:碱度、配碳比和反应时间对于珠铁中硫含量的影响较大,而对于碱度较高的含碳...     

煤粉粒度对预热含碳球团抗压强度的影响

为了弄清含碳球团配煤粒度对球团抗压强度的影响规律,研究了配加不同粒度煤粉的含碳球团在中性气氛中预热至不同温度后的抗压强度。结果表明:当温度小于1 000℃时,煤粉粒度对含碳球团的抗压强度影响不大,而当温度大于1 000℃后,煤粉粒度对含碳球团的抗压强度有显著影响;当配加煤粉的粒度介于0.074~0.106mm时,含碳球团还原后的抗压强度最高,煤粉粒度过细或过大都不利于球团强度的提高;在高温还原过程中,煤粉粒度越细含碳球团的还原速率越大,金属化率越高。     

响应曲面法优化钒钛磁铁矿含碳球团直接还原工艺

在实验室条件下模拟转底炉工艺,进行了钒钛磁铁矿含碳球团直接还原实验。运用基于中心组合设计的响应曲面法对影响钒钛磁铁矿含碳球团金属化率的主要影响因素进行了研究并优化。研究结果表明:焙烧温度对球团金属化率的影响最显著,焙烧时间次之,配碳比(wC/wO)影响最小。通过分析实验结果,建立了球团金属化率的二次多项式模型,模型预测的最佳工艺参数为:焙烧温度1 350℃,焙烧时间35.14 min,配碳比1.25。在最佳工艺条件下进行验证实验,发现实际金属化率与预测的金属化率具有良好的一致性,相对误差仅为0.87%。     

含碳球团直接还原熔分机理

为了探究含碳球团还原熔分机理,将分析纯的Fe₂O₃、氧化物和不同还原剂固结成球并进行等温还原实验,研究了温度、还原时间、配碳量、还原剂种类等条件对球团还原熔分行为的影响.进一步采用X射线衍射、扫描电子显微镜等手段表征了含碳球团在不同还原时间的微观结构及物相变化.实验结果表明:焙烧温度过低或过高含碳球团都不能良好熔分,配碳量增加可以提高球团还原和熔分速率,适宜的温度、碳氧摩尔比、还原剂分别是1400℃、1.2和煤粉.含碳球团还原熔分包括直接还原反应、间接还原反应、碳的气化反应、渗碳反应和铁的熔化反应,最后实现渣铁分离.      

低硅含镁球团矿抗压强度及冶金性能

提高入炉原料品位降低硅含量,改善冶金性能是高炉精料的主要方向。研究了低硅球团矿的还原膨胀率及MgO对低硅球团矿抗压强度和冶金性能的影响。研究结果显示,低硅球团矿虽然具有品位高,脉石含量低等优点,但随着SiO2含量的降低球团矿还原膨胀率恶化,影响高炉冶炼。低硅球团配加含镁添加剂可以有效控制还原膨胀率,同时改善球团矿的还原度和熔滴性能。球团矿SiO2的质量分数低于2%时,还原膨胀率在60%以上;当MgO的质量分数提高到2.15%以上时,还原膨胀率能降到20%以下,但随着MgO含量的增加低硅球团矿抗压强度下降,需要提高焙烧温度,才能形成稳定的铁酸镁,改善抗压强度。MgO的质量分数为2.15%时,焙烧温度要提高到1 270℃,MgO的质量分数超过2.8%以上时,焙烧温度需要提高到1 300℃。     

褐铁矿含碳球团的爆裂特性研究

根据褐铁矿含碳球团转底炉还原熔分生产粒铁的技术思想,对褐铁矿含碳球团的爆裂特性进行了实验研究.实验结果表明,褐铁矿含碳球团的爆裂与结晶水的解离有关,结晶水解离速度较快,在950℃下90s内球团中的结晶水基本上全部解离,褐铁矿含碳球团的爆裂温度约为900℃,与不含煤粉的褐铁矿球团相比约高100℃,含碳球团有利于减弱爆裂,因此,褐铁矿含碳球团的入炉温度要低于900℃.在爆裂温度以下,褐铁矿含碳球团的预热温度越低,预热时间越短,到1 300℃急速加热时,球团爆裂越严重.因此,在本实验条件下,球团最佳入炉温度约为850℃.     

菱镁矿对球团室温和低温(900℃)特性的影响

本文介绍在酸性球团中,MgO/SiO_2比值为0～1.3之间和(MgO CaO)/SiO_2比值为0～1.3之间的特性。含有MgO的焙烧球团中,铁酸镁的数量可以用球团磁化率来判定。因为磁化率是随MgO的增加而增加的。在球团中有CaO存在时,这个值又随CaO/SiO_2比值而变化。在低于1395℃时.Mg~( )扩散到赤铁矿中,MgO的密度呈条纹状分布,而当温度高于1395℃时,则按双曲线型变化,当Mg~( )在N_2气通入而扩散到磁铁矿中时。MgO密度在各种温度下均以双曲线型变化。铁酸镁的还原性略低于赤铁矿。所以,球团矿的还原性随球团中铁酸镁含量的增加而变差。在还原时,镁酸镁量的变化是很小的。球团随铁酸镁含量的增加,其膨胀率减少。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.