Recovery of heavy metals and stabilization of spent hydrotreating catalyst using a glass–ceramic matrix

High chemical stability of stoneware tiles containing waste metals

“…Galvanic waste from a metal electroplating plant from São Paulo (Brazil) with an average grain size ≈ 8 m previously analyzed 23 was heat treated at 1125 • C for 1 h in order to eliminate the CO 2 , H 2 O and SO 2 with a mass loss of 44.3 wt%, as recommended in the literature, 17 thus producing the galvanic waste raw material (GW) to be incorporated into the stoneware composition. In order to change the behaviour of the porcelain matrix and to modify the influence of the stoneware glass matrix, a recycled glass from domestic garbage (Santa Olalla e Hijos S.A. Burgos -Spain) was also used as raw materials.…”

“…A large amount of work has been carried out to validate the inertization of galvanic waste in a clay based matrix [16][17][18][19] or to develop a pigment based material by using chromium waste as precursor. [20][21][22] However an effective mechanism has not been developed up to now that allows combining the inertization aspects and a commercial product with aesthetical differences keeping the standard industrial process.…”

Molybdenum recovery as alloying agent from waste molybdenum solution

“…On the other hand this waste solution could be of great economic interest since it could be refined into chemical fertilizers [2,3]. Also there are other secondary sources of molybdenum which could be valorized, such as hydrodesulphurization (HDS) catalysts in petroleum industry [4][5][6][7], a scrap [8,9] secondary mineral sources such as low grade molybdenite concentrate generated as byproduct of uranium mining and milling operations [10]. Molybdenum compounds and his alloys could be used in a form of MoO3 and MoO2 as a catalyst in hydrocarbon reforming process [11,12], or as a electrocatalyst in fuel cell applications together with Pt and Ru [13] or as silicides of molybdenum for high temperature structural purposes [14].…”

A Bioleaching Regeneration and Recovery of Spent Refinery Catalyst Using Adapted Microorganisms

“…The approaches are either by subjecting the spent hydro treating catalyst to chemical leaching (Hydrometallurgical and Hydro-pyro metallurgical processes) or using bioleaching method in regenerating the spent catalysts [5,6]. The latter is considered simpler and cheaper in operation, higher recovery of metals, and no involvement in direct attack on the catalyst.…”