Fume leaching

There is only one day of capacity between the zinc fume recovery process in the smelter and the fume leach process in the zinc plant. Therefore, if there is an upset in the leach circuit, it is necessary to stop the slag fuming process for zinc recovery and stockpile smelter slag for recovery in the future. The same is true for the flow of residue from the zinc plant circuits to the smelter. Residue slurry is transported from the zinc plant to the smelter, where it is... 

Production. Indium is recovered from fumes, dusts, slags, residues, and alloys from zinc or lead—zinc smelting. The source material itself, a reduction bullion, flue dust, or electrolytic slime intermediate, is leached with sulfuric or hydrochloric acid, the solutions are concentrated, if necessary, and cmde indium is recovered as 99+% metal. This impure indium is then refined to 99.99%, 99.999%, 99.9999%, or higher grades by a variety of classical chemical and electrochemical processes. 

However, rotary furnaces tend to produce more exhaust gas and fumes, require more skill fill manipulation, and are more labor intensive. Also, the slags produced in the rotary furnaces, soda or fayaUte [13918-37-1] slags, normally do not pass the toxic characteristic leach procedure (TCLP) test and pose a disposal problem. 

Calcining, sintering or smelting of nickel copper matte or acid leaching or electrorefining of roasted matte Coal soots, coal tar, pitch and coal tar fumes Hardwood dusts... 

Separation and detection methods The common methods used to separate the Cr(III)/(VI) species are solvent extraction, chromatography and coprecipitation. In case of Cr(VI) from welding fumes trapped on a filter, a suitable leaching of the Cr(VI) from the sample matrix is needed, without reducing the Cr(VI) species. The most used detection methods for chromium are graphite furnace AAS, chemiluminescence, electrochemical methods, ICP-MS, thermal ionization isotope dilution mass spectrometry and spectrophotometry (Vercoutere and Cornelis 1995)- The separation of the two species is the most delicate part of the procedure. 

C. Gervais, and S. K. Ouki, Performance study of cementitious systems containing zeolite and silica fume Effects of 4 metal nitrates on the setting time, strength and leaching characteristics. J. Hazard. Mater., 93,187-200, 2002. 

These atomization techniques are used in NIOSH, AIHA, and APHA approved (recommended) methods (5-7). Although the purpose of this discussion is MS techniques, one must briefly consider collection of samples. The primary method of collecting metal dust samples and fume samples are 0.8 urn and 0.45 urn mixed cellulose ester filters. The filter is dissolved in acid or leached with dilute base, acid, or distilled water to give an analyte for MS analysis. A general procedure P CAM 173 (5), was developed by NIOSH for the analysis of metals. This method provides a starting point and standard of comparison for the analysis of metals. 

Burning herbs to ash is easy enough over a small propane stove, but there are a few problems. First there is the smoke and smell, sure to attract the attention of your neighbors and elicit moans and groans from other people of your household. Unless you have a good fume hood, this is definitely an outdoor activity. Secondly, there are some materials which refuse to get very white at all. There is a simple method we can use, called the leaching process, to obtain the salts in a purified form. 

In addition to its usefulness for environmental samples, USAL is a powerful tool for leaching metals from hygiene samples at workplaces [90], One case in point is that of filters of various materials used to collect aerosol particulates. Such filters are frequently extracted with US assistance, as in the determination of Cr(VI) in welding fumes, whereas polycarbonate membrane filters were used to collect the aerosols for subsequent leaching in an ultrasonic bath [25]. 

Derivation (1) Dust or fume from roasting zinc ores is collected, mixed with coal or coke and sodium or zinc chloride, and sintered. The cadmium fume is collected in an electrostatic precipitator, leached, fractionally precipitated, and distilled. (2) By direct distillation from cadmium-bearing zinc. (3) By recovery from electrolytic zinc process (approximately 40%). 

The spherical silicate ash particles, when viewed at close-up range appear to host a large number of sub-micron particles at the surface (Figure 6c). The microids could be silicate crystalloids precipitated from the vitrified phase or sulphate fume particles formed from the non-silicate coal minerals (18). The latter are soluble in a dilute acid (HCl) solution and Figure 6d shows the acid etched particles. Clearly, most of the microid particles were dissolved and the leach solution contained sodium and potassium sulphates. 

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