铁矿石中SiO_2,CaO,MgO,Al_2O_3的系统分析

以过氧化钠为熔剂 ,于铁坩埚内进行快速熔融试样 ,熔块以水浸取 ,硝酸溶解盐类 ,对铁矿石、球团矿、烧结矿中二氧化硅、氧化钙、氧化镁、三氧化二铝进行系统分析。与国家标准方法相比 ,本法具有操作简便 ,准确性好 ,速度快 ,成本低 ,测定范围宽等特点     

连铸保护渣中SiO_2,CaO,MgO的系统分析

试样在750℃灼烧40 min,以Na2CO3与Na2B4O7混合熔剂高温熔融处理,采用动物胶重量法测定SiO2含量,然后将滤液制成母液,用三乙醇胺掩蔽铁(Ⅲ)、铝(Ⅲ)的干扰,以EDTA滴定法测定CaO和MgO的含量。对沉淀的条件进行了选择,由于滤液中已除去硅酸,避免了二次沉淀分离。方法用于连铸保护渣中SiO2,CaO和MgO的测定,相对标准偏差分别为0.35%~0.44%,0.38%~0.51%和1.91%~2.25%;与标准方法测定结果相符合。     

白云石中SiO2-CaO-MgO的系统分析

采用过氧化钠为熔剂 ,在铁坩埚内进行快速熔融 ,对白云石中二氧化硅、氧化钙、氧化镁进行系统分析。与原标准方法相比 ,本方法具有操作简单、准确性好、分析速度快、分析成本低、测定范围宽等特点。     

ICP-AES法测定铁矿石中SiO2,CaO,MgO,Al2O3,MnO,P,TiO2等成分

采用碳酸钠和硼酸混合熔剂,用碱融法处理试样,并通过实验条件的优化,克服了引入大量基体对测定的干扰,实现了ICP-AES法对铁矿石、烧结矿中SiO2,CaO,MgO,Al2O3,MnO,P,TiO2等成分的同时测定.本方法试剂用量少,分析速度快,线性范围宽,分析结果准确、可靠.     

分析铁矿石中的Tfe SiO2 P S Al2O3 MgO CaO TiO2——X荧光光谱玻璃熔片法

本文研究了应用多道X—射线荧光光谱仪分析铁矿石中的Tfe、SiO2、P、S、Al203、MgO、CaO、TiO2，研究了熔样的方法，条件及仪器参数对分析结果的影响，并根据选定的方法采用多点标准样品法，绘制曲线。最后进行X荧光光谱法分析和标准值、化学值对照实验，效果较好，可以满足本单位生产分析。     

萤石中二氧化硅和氟化钙的系统分析

萤石试样以过氧化钠为熔剂,于铁坩埚内进行快速熔融,熔块以含硼酸的热水溶液浸取,盐酸溶解试样,制成母液。以硅钼蓝分光光度法测定二氧化硅含量,以EDTA滴定法测定总钙量,单独测定CaCO3的量用以校正总钙量从而得到CaF2含量。以硼酸消除氟的干扰,以三乙醇胺掩蔽Fe3+、Al3+,并以同品种的标准样品绘作校准曲线和采用标准样品换算的方法对数据进行处理。本方法用于萤石标准样品中SiO2,CaF2的测定,相对标准偏差分别为4.5%和1.7%,测定值与认定值一致,t检验合格。方法适用于工厂实验室的日常分析。     

强碱分离氟盐置换纯铜滴定法测定铁矿石中Al2O3

提出了强碱分离氟盐置换纯铜滴定法测定铁矿石中铝的含量。结果表明：本法准确可靠，实用性强，能满足日常分析的需要。     

精炼合成渣中SiO2、CaO、MgO、Al2O3、CaF2的测定

试样用混合熔剂熔融,稀盐酸浸取酸化、定容,移取部分试液,通过控制分析时各组分的酸度,分别用硅钼蓝光度法测定SiO2,EDTA滴定法测定MgO,强碱沉淀分离、氟化盐置换、EDTA滴定法测定Al2O3,EDTA滴定法测定CaO总量。利用CaO易被乙酸溶解,而CaF2不溶解于乙酸的特性,另称取一份试样用稀乙酸处理过滤后,将滤液定容,移取部分滤液,用EDTA滴定法测定CaO量。该方法实现了多成分联合快速测定,SiO2、CaO、MgO、Al2O3、CaF2的相对标准偏差分别<1.21%、0.16%、1.39%、0.61%和1.14%。     

碳镁球团复合脱氧脱硫剂中CaO、MgO、SiO2的测定

试样用碱熔剂熔融,稀盐酸浸取酸化、定容。移取部分试液,通过调节控制分析时各元素的酸度,利用钙镁与EGTA络合常数的对数相差5.8,在镁存在的情况下,用EGTA直接滴定钙,以EGTA掩蔽钙后,用CyDTA直接滴定镁,再用硅钼蓝光度法测定SiO2量,实现了CaO、MgO、SiO2同一母液联合快速分析。应用本法对碳镁球团中的MgO、CaO、SiO2进行测定,结果满意,RSD分别≤0.24%、2.82%和2.93%。     

分光光度法测定铁矿石中TiO_2含量

文章研究了应用分光光度计法测定铁矿石中TiO2含量的方法。方法采用混合熔剂熔融制备试样,通过实验找出最佳测定条件,使用标样和合成样品检验本方法的应用效果。方法的准确度和精密度良好。     

EDTA容量法连续测定矿石中的CaO,MgO,Al2O3

本文以玉水＋氢氟酸为溶剂，采用封闭式溶矿方法分解试样，以ＥＤＴＡ容量法连续测定矿石中的ＣａＯ、ＭｇＯ、Ａｌ＿２Ｏ＿３，经实验验证，该法简单、快速、准确度高，结果令人满意。     

ICP-AES法测定铁矿石中SiO_2,CaO,MgO,Al_2O_3,MnO和TiO_2

采用电感耦合等离子体发射光谱法对铁矿石中SiO2 ,CaO ,MgO ,Al2 O3,MnO ,TiO2 的分析进行了试验研究。试液中10mg/mLFe存在时 ,基体效应明显 ,采用基体匹配办法消除铁的干扰。Ca ,Mg ,Al,Si,Ti,Mn ,Ni,Cr ,Cu ,Co ,Zn ,V ,Ba之间没有干扰 ;稀土元素对SiO2 的测定有干扰。Al,Ca ,Mg ,Mn ,Si,Ti的检出限分别为 0.5 ,0.12 5 ,0.0 5 ,0.0 5 ,0.2 5 ,0.0 0 2 5 μg/mL ,回收     

CaO—SiO2—MgO—Al2O3精炼渣的脱硫性能

在实验室用模拟装置研究了ＣａＯ－ＳｉＯ２－ＭｇＯ－Ａｌ２Ｏ３精炼渣脱硫的性能。碱度和助溶剂ＣａＦ２含量对硫分配比Ｌｓ影响较为显著，并分析了ＭｇＯ、Ａｌ２Ｏ３对脱硫反应的作用。     

XRF光谱法测定铁矿石中的Al2O3

介绍采用X射线荧光光谱粉末压片法测定铁矿石中AL2O3从待测试样中选取一批试样,经ICP及化学分析法多次定值后,在X荧光光谱仪上绘制Al2O3的光谱强度值与Al2O3质量百分含量的工作曲线.此方法减少了不同矿种带来的基体影响.准确度和精确度都满足生产分析的需要.     

EDTA络合滴定法测定铁矿石中钙和镁

在微氨性溶液中,采用硫化钠及铜试剂使铜、铅、锌、铁、钴、镍、锰、铬、镉、铋等生成硫化物沉淀和铜试剂内络盐沉淀与钙镁分离,然后以盐酸羟胺将微量的锰还原成低价消除其干扰,用三乙醇胺和L-半胱氨酸掩蔽残留的其他金属离子。在pH10氨水-氯化铵缓冲溶液中,以酸性铬蓝K-萘酚绿B为指示剂,用EDTA络合滴定法测定钙、镁合量;另在氢氧化钾溶液中,用钙试剂为指示剂,以EDTA络合滴定法测定钙量,用差减法计算镁的含量。该方法对铁矿石标准样品中的钙和镁进行多次测定,结果与认定值相符,相对标准偏差在0.99%~3.4%(n=6)之间,加标回收率在98%~101%之间。     

Zn—EDTA络合滴定法测定铬刚玉中的Al2O3量

试样分解后,先用氨水将铝与铬、钙、镁等元素分离,再用强碱将铝与铁、钛等元素分离。在碱性溶液中加入过量的EDTA标液,调节溶液PH=5-5.5,煮沸使试液中的铝和残留离子与EDTA络合。以二甲酚橙为指标剂,用氯化锌标准溶液回滴过量的EDTA,加入氟化钠溶液,煮沸,置换Al-EDTA络合物中的EDTA,再用氯化锌标准溶液滴定被置换出的EDTA。     

ICP-AES法测定复合预熔精炼渣中Al2O3,CaO,SiO2,MgO

采用电感耦合等离子体原子发射光谱法实现了复合预熔精炼渣中Al2O3,CaO,SiO2,MgO的快速联测,对试样的分解、仪器工作条件的选择、谱线的选择以及基体干扰的消除进行了研究.通过精密度试验、不同方法之间的对比,结果表明该方法准确、可靠、快速,结果令人满意.     

Viscosity of CaO–MgO–Al2O3–SiO2 melts containing SiC particles

The influence of SiC particle on viscosity of CaO–MgO–Al₂O₃–SiO₂ melts was investigated by the rotating-cylinder method. It was found that temperature dependence of viscosity could be described by the Arrhenius law for systems with or without SiC particle addition. The activation energies of liquid–solid mixtures were mainly determined by liquid phase. Temperature had little influence on the relative viscosity (defined as the viscosity ratio of solid–liquid mixture to pure liquid). Viscosity and relative viscosity increased as decreasing rotation speed and increasing volume fraction of SiC solid particle. For the same volume fraction of SiC particle, relative viscosity was affected by the liquid slag compositions. The relative viscosity was smaller when composition of liquid slag had a larger CaO/SiO₂ ratio or MgO/Al₂O₃ ratio. Meanwhile, it was found that the smaller SiC particle will lead to a larger relative viscosity.     

Viscosity of low silica CaO–5MgO–Al2O3–SiO2 slags

Abstract

The viscosity of CaO–5MgO–Al₂O₃–SiO₂ slag with low silica was measured by rotating cylinder method up to 1823 K. Slag compositions were chosen based on five different levels of SiO₂ content between 0 and 11·80%. The MgO content was 5·0%. The mass ratio of CaO/Al₂O₃ was varied from 0·66 to 1·95. It was shown that viscosity decreased with increasing temperature and decreased with increasing the mass ratio of CaO/Al₂O₃, following by an increase with further increasing the mass ratio of CaO/Al₂O₃. The viscosity decreased with the NBO/T ratio increasing, and the trend that flow activation energy changes with the NBO/T ratio of slag was the same as the trend that viscosity changes with the NBO/T ratio. Based on the experimental data as the boundary of the homogenous phase region, the mass triangle model was used to calculate the viscosity of low silica region.     

Dissolution behaviour of MgO based refractories in CaO–Al2O3–SiO2 slag

Abstract

Magnesium oxide (MgO) based refractories are widely used in secondary refining processes, and their dissolution into refining slag is the primary cause of their shortened lifespan. The dissolution rate was investigated for sintered MgO and commercial MgO–C and MgO–Cr₂O₃ refractories in a synthesised 50CaO–45Al₂O₃–5SiO₂ liquid (mass-%) slag. The change in slag composition was measured after a refractory sample was placed into the molten slag that was stirred by flowing argon gas at 1773?K. The dissolution rate of the sintered MgO was above those of the MgO–C and MgO–Cr₂O₃ refractories under the same gas flowrate, although the dissolution rate of all samples increased as the gas flowrate was increased from 25 to 75?mL·min^??1. The slag containing 5?mass-% FeO considerably promoted the dissolution of the MgO–C refractory because of the oxidation of carbon by FeO. The dissolution of all the refractories was greatly affected by penetration of the liquid slag, with the mass transfer of MgO in the penetrating slag at lower gas flowrates likely being the rate controlling step. At high gas flowrates, Ar bubbles covered the surface and blocked the contact between the liquid slag and the solid phase, reducing the dissolution rate.