Valorisation of red gypsum through understanding of structure-processing-property relationships across scales

通过理解跨尺度的结构-加工-性能关系来评估红石膏的价值

• 批准号: 2746338
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2746338
• 关键词: Valorisation; red; gypsum; through; understanding

Effective and consistent filtration of mineral suspensions can be hindered by undesirable rheological effects when moisture content of the mineral phase/s is high. Red gypsum is such a material and is produced when waste sulfuric acid from titanium dioxide manufacture is neutralised with limestone, lime, or a combination of the two. Sustainable utilisation of red gypsum is low and significant volumes are wasted in landfill annually, due to handling difficulties and high levels of impurities. Previous work has focused on elemental and microscopic analysis of red gypsum to suggest potential uses, but there is less understanding of the relationships between the process conditions, structural development of particles, and the resulting performance [1]. In this work, samples of industrial red gypsum will be characterised to investigate particle morphology and the presence, quantity, and state of impurities or additional phases. These will be linked to performance measures based on filtration and rheology to identify potential sources of undesirable behaviour. It is important to understand the level of dewatering of red gypsum that is required to avoid behaviour such as thixotropy, and how the incorporation of this water into the mineral structures makes it difficult to filter. In particular, particle shape and size distributions should be controlled alongside the presence of impurities and additional phases when considering permeation of water through a filter cake, in order to avoid potential build-up of smaller particles or impurities at the filter medium. Replication of the gypsum crystallisation process at the lab scale with increased process control will allow isolated changes in conditions to identify resulting differences in characteristics and performance, a step that is currently not possible at the process scale. Developing an understanding that can lead to improvement in the structural characteristics of red gypsum can contribute to increased utilisation and a reduction in waste of this potentially valuable process by-product.

当矿物相/s的水分含量较高时，矿物悬浮液的有效过滤可能会受到不良的流变效应的阻碍。红色石膏是一种材料，当二氧化钛制造的废硫酸用石灰石，石灰或两者的组合中和时会产生。红色石膏的可持续利用率低，由于处理困难和高质量杂质，每年浪费大量垃圾填埋场。先前的工作集中在红色石膏的元素和显微镜分析上，以暗示潜在用途，但是对过程条件，颗粒的结构发展和由此产生的性能之间的关系较少了解[1]。在这项工作中，将对工业红色石膏的样品进行表征，以研究颗粒形态以及杂质或其他阶段的存在，数量和状态。这些将与基于过滤和流变学的绩效指标联系起来，以确定不良行为的潜在来源。重要的是要了解避免诸如触变拷贝之类的行为所需的红色石膏的脱水水平，以及将这种水掺入矿物结构如何使其难以过滤的水平。特别是，在考虑通过过滤蛋糕渗透到水时，应与存在杂质和其他相位的颗粒形状和大小分布，以避免潜在的较小颗粒或过滤器培养基处的杂质。在实验室量表上以增加过程控制的石膏结晶过程的复制将允许孤立的条件变化，以识别产生的特征和性能差异，这一步骤目前在过程量表上是不可能的。建立一种可以改善红色石膏结构特征的理解可以有助于增加利用率，并减少浪费这种潜在有价值的过程副产品。