Molybdenum disulphide (MoS2) has been one of the most interesting materials for scientists and engineers for a long time. While its bulk form has been in use in conventional industries as an intercalation agent and a dry lubricant for many years, its two-dimensional forms have attracted growing attention in recent years for applications in nano-electronic applications. Specifically, the single layer form of MoS2 shows significant potential as a semiconductor analogue of graphene. These exciting applications are spread over many fields, from flexible and transparent transistor devices, to low-power, high efficiency biological and chemical sensing applications. This Review Article, for the first time, provides a comprehensive overview of the synthesis, structural polytypes, properties, and applications of bulk, few layer, and single layer MoS2.

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Synthesis and properties of molybdenum disulphide: from bulk to atomic layers

A literature review of the recovery of molybdenum and vanadium from spent hydrodesulphurisation catalysts: Part I: Metallurgical processes

Selective recovery of molybdenum from spent HDS catalyst using oxidative soda ash leach/carbon adsorption method.

https://estudogeral.sib.uc.pt/bitstream/10316/5452/1/file03600a734caa4782ab96e0085c0310b5.pdf

Toxicity of Sodium Molybdate and Sodium Dichromate to Daphnia magna Straus Evaluated in Acute, Chronic, and Acetylcholinesterase Inhibition Tests

Mo is an essential trace element for both plants and animals in low concentrations (<5 ppm). However, provoked by uncontrolled industrial waste releases in freshwater or seawater, it is plausible that excessive availability of soluble Mo(VI) would be potentially toxic. In the environment, soluble Mo(VI) is mainly present in anionic forms of molybdate (MoO4 2−) and/or tetrathiomolybdate (MoS4 2−). The fate and transport of soluble Mo(VI) anions in surface and subsurface aquatic environments is typically controlled by adsorption in acidic soils and sediment. As such, the ability of soils/bed sediments to retain Mo(VI) is a key to determine its general mobility in the aquatic environment. This article reviews the sources and distribution of Mo speciation in solution and Mo(VI) anions adsorption mechanisms in soils and bed sediments, and evaluates the surface adsorption complexation models at the solid-water interface to estimate Mo(VI) anions adsorption in these chemical systems. Mo(VI) anions adsorption mec...

A Review of Molybdenum Adsorption in Soils/Bed Sediments: Speciation, Mechanism, and Model Applications

The article contains sections titled:



1.	Introduction	
2.	Properties	
3.	Occurrence	
3.1.	Minerals	
3.2.	Deposits	
4.	Production	
4.1.	Concentration	
4.2.	Processing of Concentrate	
4.3.	Recovery from Spent Petroleum Catalysts	
4.4.	Recovery during Production of Tungsten Ores	
4.5.	Production of Molybdenum Metal Powder	
4.6.	Production of Compact Molybdenum Metal	
4.7.	Processing of Molybdenum	
4.8.	Molybdenum-Base Alloys	
5.	Uses	
6.	Production of Ferromolybdenum	
6.1.	Ferromolybdenum Grades	
6.2.	Raw Materials	
6.3.	Submerged Arc Furnace Carbothermic Reduction	
6.4.	Metallothermic Reduction	
7.	Molybdenum Compounds	
7.1.	Overview of Molybdenum Chemistry	
7.2.	Molybdenum Oxides	
7.3.	Molybdenum Chalcogenides	
7.4.	Molybdenum Halides	
7.5.	Molybdates, Isopolymolybdates, and Heteropolymolybdates	
7.6.	Other Molybdenum Compounds	
8.	Uses of Molybdenum Compounds	
8.1.	Catalysis	
8.2.	Lubrication	
8.3.	Corrosion Inhibition	
8.4.	Flame Retardancy and Smoke Suppression	
8.5.	Pigments	
8.6.	Agriculture	
9.	Analysis	
10.	Economic Aspects	
11.	Environmental Aspects	
12.	Toxicology and Occupational Health

Molybdenum and Molybdenum Compounds

Molybdenum is recovered from an ammonium molybdate solution containing phosphate anions by digesting in an ammonium molybdate solution at least one water-soluble compound of at least one metal selected from the group consisting of aluminum, calcium, iron and magnesium in small but effective amounts to precipitate at least about 50% of the phosphate anions for a time sufficient to precipitate the phosphate anion, separating the phosphate precipitate from the ammonium molybdate solution, then acidifying the ammonium molybdate solution with at least one mineral acid selected from the group consisting of sulfuric acid and nitric acid to lower the pH value of the solution to between about 2.5 and about 4.5 to precipitate ammonium polymolybdate, and calcining the ammonium polymolybdate at a temperature below about 750° C. to produce a molybdenum trioxide product.

Production of molybdenum oxide from ammonium molybdate solutions

A process is provided for recovering metal values from spent hydrodesulfurization catalyst, the process comprising forming in a pressure reactor an aqueous slurry of finely divided spent catalyst and sodium carbonate, the spent catalyst containing by weight about 2 to 10% Mo, up to about 12% V (e.g., about 2 to 10%), about 0.5 to 4% Co, up to about 10% Ni (e.g., about 0.5 to 5%), occluded oil, coke, sulfide sulfur and the balance essentially alumina. The amount of sodium carbonate employed is at least sufficient under oxidizing conditions to convert molybdenum and any vanadium present to soluble Na2 MoO4 and NaVO3 and to neutralize SO3 produced during oxidation, the amount of sodium carbonate being at least that required stoichiometrically. The slurry is heated to a temperature of about 200° C. to 350° C. (e.g., 275° C. to 325° C.) and a pressure of about 800 psig to 2500 psig (e.g., about 1500 psig to 2500 psig) for a time at least sufficient to solubilize the molybdenum and vanadium present, the amount of oxygen employed being over about 1.1 times the stoichiometric amount sufficient to oxidize the metal values and sulfur to the maximum oxidized state, and to oxidize the oil and free carbon to CO2 and H2 O. The solubilized Mo and V are thereafter separated from each other.

Recovery of metal values from spent hydrodesulfurization catalysts

Molybdenum is recovered from an organic material, such as a spent epoxidation catalyst, by heating the material in a stream of non-oxidizing gas at a temperature of at least about 400° C. to evolve the organic in the gas stream from which it is recovered and to leave a powdery residue containing essentially all of the molybdenum.

Roger F. Sebenik

Papers

Molybdenum and Molybdenum Compounds

Production of molybdenum oxide from ammonium molybdate solutions

Recovery of metal values from spent hydrodesulfurization catalysts

Recovery of molybdenum from spent catalyst solutions obtained from hydroperoxide epoxidations