Plant solutions

The effect of impurities in either structural material or corrosive material is so marked (while at the same time it may be either accelerating or decelerating) that for rehable results the actual materials which it is proposed to use should be tested and not types of these materials. In other words, it is much more desirable to test the actual plant solution and the actual metal or nonmetal than to rely upon a duphcation of either. Since as little as 0.01 percent of certain organic compounds will reduce the rate of solution of steel in sulfuric acid 99.5 percent and 0.05 percent bismuth in lead will increase the rate of corrosion over 1000 percent under certain conditions, it can be seen how difficult it would be to attempt to duplicate here all the significant constituents. 

A serious drawback is the large amount of CAN (up to 2.5 molar amounts) needed. Cerium salts are highly toxic pollutants and must be removed from industrial effluents and wastewaters. Cerium (III) solutions from penem pilot plant solutions containing up to 1.2 M Ce(III) were recycled in a two compartment Electro Syn Cell. Typical recycling conditions Nation diaphragm with coated Ti-anode, applied current densities = 50-150 A/em2 yield > 90% processed amount about 475 kg CAN [46,126,136,137], The simultaneous determination of Ce(III) and Ce(IV) in the pilot plant solution and in solid CAN can be performed polarographically. As little as 0.3% Ce(NH4)2(N03)5 can be determined in Ce(NH4)2(N03)6 [136]. 

Cocker, K.M., Evans, D.E., and Hobson, M.J., The amelioration of aluminium toxicity by silicon in higher plants solution chemistry or an in planta mechanism Physiol. Plant., 104, 608, 1998. 

During development, evaluation of the consolidated materials was based primarily on two criteria, leachability and the concentration factor, i.e., the concentration of waste oxides on a volume basis. The concentration factor is directly affected by the residual porosity in a consolidated waste as well as by the dilution caused by the addition of consolidation aids. This factor can be as high as 1.2 g/cm3 for a fully dense ( 5 g/cm ) titanate waste prepared from the projected Barnwell plant solution composition. The factor is slightly lower for a titanate waste containing silicon and zeolite additions, which has a typical density of U.2 g/cm3. The leachability was determined by an "instantaneous leach test developed for fast, comparative evaluations of materials, the details of which are described elsewhere (l6). 

In plant solutions, up to 70% of the Ru(NO) 3+ may be in the form of inextractable nitrito complexes.305 However, as the nitrato species extract the mass action affect of the nitrate present may lead to the substitution of nitrite with nitrate, even though the former gives the more... 

Typical activator concentrations in plant solutions are 0.3 to 1.0 wt. % ACT-1 compared to about 3 wt. % for DEA. The overall activator consumption costs are estimated to be about the same for ACT-1 and DEA. However C02 Slip with ACT-1 is about half of that achieved with DEA 206. 

In the metal refining of ores, the metal is solubilized in an aqueous solution. The optical control of metal refining requires quick, accurate analysis of the major chemical species present in solution. Raman spectroscopy and resonance Raman are used to identify the amine complexes of Co, Ni, and Cu species, as well as ammonia sulfate and sulfamate, present in these industrial solutions. The Raman spectra of an industrial plant solution from mine tailings are shown in Fig. 7-15. Each solution contains one or more metal species, sulfate, sulfamate, ammonia, ammonium sulfate, and water. From a comparison with model ammine complexes, the vibrations in the spectra are identifiable. Bands were observed at 615, 980 and 1,110 cm-1 and were assigned to the sulfate ion. No bands were observed for free ammonia. A band at 376 cm-1 was assigned to the Ni(NH3)j + specie. A band at 490 cm-1 was assigned to the Co(NH3)g+ specie. 

Cation exchange experiments were performed with gel and macroporous resins, and with both simulated and authentic plant solutions. Scouting experiments showed that Dowex 50W x 8 was the most effective cation resin tested. Complexing of Fe + with oxalate ion was also necessary to obtain adequate column capacity. Test data are summarized in Table II. 

In situ leach, mine water, water-treatment plant solutions... 

Osmosis contributes to the movement of water through plants. Solute concentrations increase going from soU to root cells to leaf cells, and the resulting differences of osmotic pressure help to draw water upward. Osmosis also controls the evaporation of water from leaves by regulating the size of the openings (stomata) in the leaves surfaces. 

B. Grigorova, S.A. Wright and M. Josephson. Separation and determination of stable jnelallo c a-nide complexes in metallurgical plant solutions and effluents by reversed-phase ion-pair chromatography,/ Chromaiogr., 410,19,1987. 

Another tendency consolidated in the third phase is the use, when possible and advantageous, of plant solutions based on intrinsic or passive safety. 

An idea of the total plant solution available is seen in Figure 5. This range of solutions allow Outotec to tailor a well integrated process to specific client needs, ensuring cost efficiency and maintaining high environmental standards. 

Soluble neutron absorbers are proposed for criticality safety control in future processes at the Idaho Chemical Processing Plant. Solutions of neutron poisons have been used in the past for criticality control in processing various reactor fuels. No problems were encountered in the safe use of the neutron poisons although dissolution of different types of foel occasionally required reevaluation of the poison ccmcentrations. Proposed plans include the uses of soluble neutron poisons in the Rover fuel dissolver, the Fluorinel dissotyer, and in increased concentrations in the electrolytic dissolver. The purpose of this paper is to present these proposals and to discuss the criticality safety aspects. 

In a recent investigation of the corrosion resistance of as-welded C-276, C-22, and alloy 686 specimens, Saldanha [47] has shown that such weld metal is also susceptible to rapid and severe pitting in a simulated plant solution, boiling 80 % acetic acid with 1000-5000 ppm ferric chloride. There was severe pitting on all three alloy weldments see Fig. 23 for pitting in C-276 weld metal in only five days of testing. There was no attack in the heat-affected zones or in the base-plate. Thus, there are plant environments in which... 

Laboratory tests with reagent chemicals in place of plant solutions... 

When simulating conditions such as concentration or condensation, it is useful to know the exact composition of the condensate. Thermodynamic modeling may be used to calculate the composition of the condensate. Contaminants, such as oxygen or chlorides, also need to be accounted for if they are present in the plant solution. 

In general, the slow strain rate test is a conservative test and a useful method for determining whether an alloy is resistant to stress corrosion cracking in a plant solution. 

Plant type Polybutadiene plant Solution SBR plant Styrenic block copolymer plant... 

According to Butwell et al. (1982), the approximate removal efficiencies by MEA and DEA plant solutions ate as follows ... 

The vapor pressures of the individual components of typical plant solutions have been determined by Zhavoronkov (1939). One set of his data is presented in Figure 16-23 as a plot of pressure versus temperature on a log p versus 1/T scale. 

Plant solutions are normally prepared by dissolving metallic copper in a mixture of ammonia, acid, and water. The use of distilled water is desirable since chlorides or sulfates, which may be introduced with less-pure water sources, can result in corrosion. It is necessary to blow air into the dissolver to oxidize the copper to the cupric state, and the cupric copper that is formed is capable of dissolving additional elemental copper by oxidizing it to the soluble cuprous form. The reaction is also of value as a means of controlling the cupric/cuprous ion ratio in the solution as it is made. Careful control of ammonia and acid concentrations is also required. An excess of acid relative to aimnonia can cause the solution to become corrosive, while insufficient ammonia or acid can result in the precipitation of copper compounds. 

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