Studies in chemical phase analysis. Part I. Determination of the solubilities of elements in certain organic solvent-bromine mixtures

Abstract

As part of a study on the quantitative separation of carbide, nitride, oxide and sulphide inclusions from metals, the solubilities of aluminium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, niobium, phosphorus, silicon, sulphur, tin, titanium, tungsten and vanadium have been determined a t 25 "C in organic solventbromine mixtures (10 + 1 V / V ) after refluxing. The solvents were methyl acetate, butyl acetate and acetonitrile. All of the above elements except lead, molybdenum, silicon and tungsten were appreciably or very soluble in these solvents. Molybdenum was sparingly soluble and the others almost insoluble.

Removal of metallic coatings from rare-earth permanent magnets by solutions of bromine in organic solvents

“…A signicant solubility of iron, but also of cobalt, in bromine solutions have been reported, but reux conditions were applied in that case. 24 Less copper than nickel dissolved in the rst minutes of the process for Sm-Co PMs and this can be explained by the fact that copper is the middle layer of the coating, covered by nickel that needs to be dissolved prior to the copper dissolution. In case of Nd-Fe-B PMs, the situation was reversed: more copper than nickel dissolved in the rst minutes and this might be explained with a thinner rst layer of nickel for the Nd-Fe-B PMs compared to the Sm-Co PMs.…”

“…In the literature, bromine in organic solvents such as ethyl acetate or methanol has been reported to be able to dissolve metals such as uranium, thorium, zirconium, titanium, iron, chromium and nickel. [19][20][21][22][23][24] Inspired by these results, we investigated the dissolution of the nickel-copper-nickel coating of SmCo 5 , Sm 2 Co 17 and Nd-Fe-B PMs in solutions of 1 vol% bromine in ve organic solvents: ethylene glycol (EG), ethanol (EtOH), dimethylformamide (DMF), ethylacetate (EtOAc) and methyl acetate (MeOAc).…”

Oxidative Dissolution of Metals in Organic Solvents

“…The study of the solubility showed that most of the metal bromides can dissolve in the organic solvent–bromine mixtures, but some metal bromides were poorly soluble, such as the bromides of lead, molybdenum, silicon, and tungsten. 21 The poor solubility of metal bromides could limit the oxidative dissolution of these metals in the leaching systems. Most studied carbides, nitrides, and oxides of metals have low reactivity and solubility in Br 2 -ACN and Br 2 -MeOAc, whereas most sulfides have a significant solubility and some sulfides can react with the leaching agents violently.…”

“…Examples of commonly used organic solvents are ethanol (EtOH), methyl acetate (MeOAc), butyl acetate (BuOAc), ethylene glycol (EG), acetonitrile (ACN), and tri- n -butylphosphate (TBP). A major application of organic solvent–halogen mixtures is the quantitative analysis of nonmetallic phase impurities in metals and alloys, because the metals in their elemental state are oxidatively dissolved, but metallic compounds (e.g., oxides and borides) and nonmetallic components (e.g., boron) are not soluble. − Other applications are the dissolution of metals or metal alloys, the chlorination of metals, and the chemical etching and polishing of semiconductors. ,− Leaching systems containing halogens and organic solvents used for dissolution of metals in various application fields are summarized in Table . Due to the large variety of combinations of halogens with organic solvents, this subsection is further divided into three subsections based on the type of halogens.…”

“…All nitrogen was recovered as insoluble aluminum nitride after dissolution of steel samples in the lixiviant. Inspired by this work, Headridge and co-workers investigated the feasibility of quantitative separation of carbide, nitride, oxide, and sulfide inclusions from metals by using solutions of halogens in organic solvents. − For useful phase analysis, it is necessary that only the metals in their elemental state oxidatively dissolve in the leaching system, and other compounds such as oxides and nitrides that are present in metal alloys do not. Therefore, the reactivity of various metals in the elemental state and of metal compounds (oxides, nitrides, sulfides, carbides) with bromine in organic solvents MeOAc, BuOAc, and ACN was investigated.…”