New process for treating boron-bearing iron ore by flash reduction coupled with magnetic separation

Boron is an important industrial raw material often sourced from minerals containing different compounds that cocrystallize,which makes it difficult to separate the mineral phases through conventional beneficiation.This study proposed a new treatment called flash reduction-melting separation(FRMS)for boron-bearing iron concentrates.In this method,the concentrates were first flash-reduced at the temperature under which the particles melt,and the slag and the reduced iron phases disengaged at the particle scale.Good reduc-tion and melting effects were achieved above 1550℃.The B_(2)O_(3) content in the separated slag was over 18wt%,and the B content in the iron was less than 0.03wt%.The proposed FRMS method was tested to investigate the effects of factors such as ore particle size and tem-perature on the reduction and melting steps with and without pre-reducing the raw concentrate.The mineral phase transformation and morphology evolution in the ore particles during FRMS were also comprehensively analyzed.

Properties of boron-rich slag separated from boron-bearing iron concentrate

In the present paper,the fundamental research on the properties of boron-rich slag melting separated from boron-bearing iron concentrate was performed.The melting and fluidity of B2O3–MgO–SiO2–FeO slag system,crystallization of separated boron-rich slag and factors on the extraction efficiency of boron-rich slag were systematically investigated.B2O3 content would heavily affect the melting and fluidity property of boron-rich slag.Generally,FeO could improve the melting and fluidity property of boron-rich slag.Boron-containing crystalline phase mainly precipitated in temperature range from 1200°C to 1100°C.Higher smelting temperature and B2O3 reduction ratio were negative for the extraction of boron.The cooling rate of 10–20°C/min was better for the crystallization of boron-containing crystalline phase.Based on the obtained experimental results,the optimum operating parameters for the development of pyrometallurgical boron and iron separation process and further boron-rich slag cooling process were proposed.

硼铁矿应用于高铬型钒钛矿烧结优化的实验研究

实验室条件下,研究了硼铁矿对高铬型钒钛矿烧结工艺及冶金性能的影响.研究表明:随着硼铁矿质量配比的升高,垂直烧结速度、成品率、转鼓指数、烧结杯利用系数、综合指标及低温还原粉化性能均呈先升高后降低的趋势,在硼铁矿质量配比为5.0%时,以上各指数均达到最高值,分别为28.84 mm·min-1,86.02%,61.2%,1.919 t·(m2·h)-1,363及90.76%,均优于未配加硼铁矿时的烧结矿性能.因此,烧结矿性能得以优化,可以为高炉冶炼提供更为优质的高铬型钒钛烧结矿.

某细粒含锰褐铁矿焙烧-磁选试验研究

湖南某含锰铁矿铁矿物嵌布粒度细、锰含量高，本文采用磁化焙烧‐磁选工艺进行铁的可利用性研究，并对磁化焙烧产品进行了X射线衍射分析和显微形貌分析。研究表明，在焙烧温度为850℃、时间60min、煤炭加入量4％条件下得到的磁化焙烧产品，控制磨矿细度－325日85％～90％，在159kA／m的磁选场强下，经过三次精选，可以得到铁品位55．72％、锰品位为7．03％的铁精矿，铁回收率达到80.84％；磁化焙烧产品中主要矿物为磁铁矿，大部分的磁铁矿嵌布粒度细，与锰矿物、脉石以集合体的形式存在，磁铁矿难以实现单体解离。

Mechanism of Strength Improvement of Magnetite Pellet by Adding Boron-bearing Iron Concentrate

The mechanism of improving compressive strength of magnetite pellet by adding boron-bearing iron concentrate was studied. Boron-bearing iron concentrate and magnetite were mixed, pelletized and roasted under differ ent roasting conditions. Then, compressive strength of pellets was tested, and polished sections of the roasted pellets were analyzed from the perspective of mineralogy. Finally, the effects of different proportions, roasting temperatures and roasting time of boron-bearing iron concentrate on the compressive strength of magnetite pellets were investigated and explained.

Reduction and melting separation mechanism of boron-bearing iron concentrate/coal composite pellet

Realizing the boron and iron separation through selective reduction and melting separation of boron-bearing iron con- centrate is of great significance for the utilization of crude ludwigite. The reduction and melting separation mechanism of boron-bearing iron concentrate/coal composite pellet was systematically investigated. The reduction and melting separation test of small size pellet was performed to reveal the evolution of slag and iron in the melting separation process. The isothermal reduction experiment showed the relationship between reduction stage and melting separation stage, and the step reduction and melting separation was perfectly achieved. Coal particles existed through the reduction and melting separation process and finally formed brown residue around the separated product. The pellet could not realize melting separation when the B2O3 content in the concentrate was lower than 6.00 wt%.

螺旋磁场磁选机在铁矿的精选试验研究

介绍了螺旋磁场磁选机的结构特征、工作原理及特点。用某选矿厂的铁精矿在实验室进行了螺磁机的单元格精选试验,精矿品位比精选前提高2～6个百分点。用φ600螺磁机进行了铁精矿的现场精选工业试验,取得了初步成功。

地球深处形成含硼金刚石的可行机制

近年来,以“希望之钻”为代表天然蓝色钻石(蓝钻)的形成机制引起科学界和大众的广泛兴趣.天然蓝钻是形成于地球最深处的珍贵矿物,含约0.011~10μg/g棚杂质.现行地球化学模型表明地球内部硼元素主要富集于大陆和大洋地壳,极难进入地球内部的下地幔深度.蓝钻的存在为地球下地幔环境中存在硼元素提供了有力证据,然而其地质起源与循环机制是当前领域内亟待解决的科学难题之一.在本研究中,我们提出金属硼化物随地球板块运动进入下地幔深处,在高温高压环境下与碳酸盐发生氧化还原反应,从而形成蓝钻的物理机制.通过第一性原理计算提出了多种可能形成蓝钻的化学反应途径,并在下地幔压力与温度条件下(22.5 GPa,2100 K),利用CaCO_(3)和FeB的直接氧化还原反应,成功制备“类天然”蓝钻.这一发现揭示了地球深处蓝钻形成之谜,并为进一步深入探索地球内部的物质循环和矿物形成机制提供了新思路.