Chlorination roasting-coupled water leaching process for potash recovery from waste mica scrap using dry marble sludge p
- PDF / 1,827,891 Bytes
- 13 Pages / 592.8 x 841.98 pts Page_size
- 88 Downloads / 184 Views
Chlorination roasting-coupled water leaching process for potash recovery from waste mica scrap using dry marble sludge powder and sodium chloride Sandeep Kumar Jena, Jogeshwar Sahu, Geetikamayee Padhy, Swagatika Mohanty, and Ajit Dash Mineral Processing and Central Characterization Department, Council of Scientific and Industrial Research (CSIR)-Institute of Minerals and Materials Technology (IMMT), Bhubaneswar, Odisha 751013, India (Received: 23 October 2019; revised: 11 December 2019; accepted: 1 February 2020)
Abstract: The present paper reports the effective utilization of marble sludge powder (MSP) for the recovery of potash values from waste mica scrap using chlorination roasting –water leaching method. Characterization studies indicated the presence of dolomite as the major mineral phase in MSP, whereas muscovite and quartz were observed in the mica sample. The acid leaching studies suggest a maximum of 22% potash recovery under conditions: 4 M H2SO4 acid, particle size of ~100 μm, stirring speed of 600 r/min, leaching temperature of 75°C, and leaching time of 90 min. The chlorination roasting–water leaching process was adopted to achieve the lowest level of 80%–90% potash recovery. The optimum conditions for the recovery of ~93% potash from mica (~8.6wt% K2O) requires 900°C roasting temperature, 30 min roasting time, and 1:1:0.75 mass ratio of mica : MSP : NaCl. The roasting temperature and amount of NaCl are found to be the most important factors for the recovery process. The reaction mechanism suggests the formation of different mineral phases, including sylvite (KCl), wollastonite, kyanite, and enstatite, during roasting, which were confirmed by X-ray diffraction (XRD) analyses and scanning electron microscopy (SEM) morphologies. The MSP-blended NaCl additive is more effective for potash recovery compared with the other reported commercial roasting additives. Keywords: potash recovery; mica scrap; marble sludge powder; chlorination roasting; water leaching
1. Introduction The generation and steady increase of ineffectual solid waste materials due to industrial, mining, agricultural and commercial activities owing to increasing urbanization and growth of population creates various problems in their disposal and recycling; so, there is a need to reduce, recycle, reuse or recover the generated solid wastes as much as possible. Marble sludge powder (MSP), which is generated in marble processing industries during sawing and polishing of marble, is one of the major industrial solid wastes. Marble sludge, in the form of semi-liquid or slurry form, contains around 24wt%–45wt% water along with dust marble particles and 20% of the processed marble is estimated to end up in sludge waste [1–2]. Practically 70% of the total mine’s production is discarded as waste during mining, processing, and polishing, resulting in significant environmental issues [2–4]. As per the available data, the world’s major marble exporters including Turkey, Italy, China, Greece, Spain, and India, produce a substantially high amount of marb
Data Loading...
