ABSTRACT

Multi-gravity separator (MGS) is a centrifugal gravity separator deployed for beneficiation of fine particles with relatively low concentration. It is for the first time that a statistical tool was engaged to evaluate effects of the most influencing process variables and their actual impact upon the performance of MGS with respect to its potential to clean the difficult-to-wash low volatile coking (LVC) coal fines. Characteristics of LVC coal sample were analyzed and discussed in terms of physical properties, petrographic composition, washability, XRD and SEM analysis. Three different feed sizes such as – 500 μm, – 250 μm and – 150 μm were used for assessing the separation mechanism and efficacy of MGS along with three different process variables such as drum speed, shaking amplitude and wash water rate to study and ascertain the most efficient experimental design for obtaining optimal result. Results revealed that drum speed and feed size turned out to be most significant parameters for reduction of ash concentration. In design of experiments, clean coal ash, combustible recovery and separation efficiency were considered as response functions. Material balance for MGS unraveled that about 74% clean coal produced with 10% ash reduction from the feed ash of 32.8% could be achieved in single stage, in optimized process conditions.

摘要

多级重力分离机（MGS）是一种离心式重力分离机，用于对浓度相对较低的细颗粒进行选矿。这是第一次使用统计工具来评估影响最大的过程变量的影响及其对 MGS 性能的实际影响，以了解其清洁难洗低挥发性焦化 (LVC) 煤的潜力罚款。从物理性质、岩相成分、可洗性、XRD和SEM分析等方面对LVC煤样的特性进行了分析和讨论。三种不同的进料尺寸（例如 – 500 μm、– 250 μm 和 – 150 μm）用于评估 MGS 的分离机制和功效以及三个不同的工艺变量，例如转鼓速度、振动幅度和洗涤水速率来研究和确定获得最佳结果的最有效的实验设计。结果表明，转鼓速度和进料尺寸是降低灰分浓度的最重要参数。在实验设计中，将洁净煤灰、可燃物回收率和分离效率作为响应函数。MGS 的物料平衡表明，在优化的工艺条件下，单阶段可以实现约 74% 的清洁煤，从 32.8% 的原料灰中减少 10% 的灰分。可燃物回收和分离效率被认为是响应函数。MGS 的物料平衡表明，在优化的工艺条件下，单阶段可以实现约 74% 的清洁煤，从 32.8% 的原料灰中减少 10% 的灰分。可燃物回收和分离效率被认为是响应函数。MGS 的物料平衡表明，在优化的工艺条件下，单阶段可以实现约 74% 的清洁煤，从 32.8% 的原料灰中减少 10% 的灰分。