Microwave-assisted thermal treatments for producing Nanoparticle pigment

颜料生产有微波辐射可替代的脱水、预热、焙烧等热处理工序。在纳米颗粒料浆的脱水过程中，过滤性能和浓缩性能都会受到负面影响。纳米颗粒会降低性能或堵塞滤布内部的多孔空间。因此，过滤应作为间歇过程进行，性能较低。此外，纳米颗粒对浓缩操作造成了严重的问题，包括颗粒沉降慢，停留时间增加，以及较大的絮凝剂消耗。对于颜料浆料，低功率微波处理可作为过滤的替代品，并可在有或没有增稠剂的情况下工作。与脱水相比，微波焙烧要复杂得多，因为它预计会产生更高的温度，并改善物理相变。本研究工作将集中在微波辅助脱水和焙烧方面。Argex钛公司正在开发一种生产氧化钛颜料的新技术。预热、脱水和焙烧是生产线的一部分。因此，可以使用微波辅助加热对这些进行预热、脱水和焙烧。开发这一新的微波辅助热处理技术将为加拿大颜料行业带来更低的能耗、更好的工艺控制和更高的工艺效率，其优势将增加颜料厂的盈利能力。

Pigment production has thermal treatment stages that can substituted by microwave radiation such asdewatering, preheating and calcination. In dewatering of Nanoparticle slurry, performances of both filtrationand thickening are affected negatively. Nanoparticles reduce performance or block porous space inside filtercloth. Therefore, filtration should be done as a batch process with low performance. Also, nanoparticles causeserious problems for thickening operation including slow particle settling, increase in residence time, andbigger flocculant consumption. For a pigment slurry, low power microwave treatment can be used as asubstitute for filtration, and work with or without thickener. Microwave application for calcination is morecomplicated compared to dewatering, because it is expected to generate higher temperatures as well as improvephysical phase transformation. This research work will focus on microwave-assisted dewatering andcalcination. Argex Titanium Incorporated, is developing a novel technology for producing titanium oxidepigment. Preheating, dewatering and calcination stages are part of the production line. Therefore,microwave-assisted heating can be used for these preheating and dewatering and calcination. Developing thisnovel microwave-assisted thermal treatment technique will lead to less energy consumption, better control onthe process and higher process efficiency for Canadian pigment industry the advantages of which will increasethe profitability of the pigment plant.