Potassium chlorate

About: Potassium chlorate is a research topic. Over the lifetime, 622 publications have been published within this topic receiving 3555 citations.

Treatment of Cr(VI)-containing Mg(OH)2 nanowaste.

Abstract: Nanomaterials can be very effective for adsorbing heavy metals and organic pollutants from waste water, whereupon they are transformed into so-called nanowastes that can be particularly complex in composition, highly stable in size, and difficult to precipitate. Investigations related to the disposal of these hazardous pollutant-adsorbed nanowastes are yet to be reported. It has been recognized recently that some traditional industrial sludges are actually nanowastes with adsorbed heavy metals or organic pollutants. For example, Chinese chlor-alkali and chlorate plants generate over 800 kilotons of Mg(OH)2-containing nanowastes per year. [3–5] These nanowastes have a high surface-adsorption affinity and sometimes contain tightly bound poisonous heavy metals or have dioxinlike toxicity. The Mg(OH)2 nanowastes generated by the sodium and potassium chlorate industries in China, for example, are typically adsorbed with the carcinogenic heavy metal chromium(VI) (see Figure S1 in the Supporting Information). As illustrated in Figure 1, landfill after solidification is the conventional method for disposing of toxic Cr sludge. Herein we report an effective strategy for disposing of the above-mentioned Cr-containing nanowastes. Transforming Mg(OH)2 nanoparticles into bulk materials releases the adsorbed Cr into solution. This Cr-containing solution can subsequently be recycled in the chlorate process and the detoxified solids can potentially be reutilized as additives in other applications, such as in ceramics, paint, flame-retardant engineering plastics, or lubricants. The present approach could lead to alternative solutions for dealing with other nanosized pollutants. Typical Cr-containing nanowastes consist of about 50% water, 2048 mgkg 1 of Cr, 30% of 20-nm Mg(OH)2, and 16% of 100-nm CaCO3. The pH of the waste is around 9. The viscous solid is quite difficult to separate from chromate solutions by any centrifugation, washing, or filtration methods. However, addition of a suitable mineralizer to the nanowastes during hydrothermal coarsening might accelerate the crystal-growth speed of nanoparticles or transform them into compounds with reduced surface adsorption properties. A systematic survey of suitable mineralizers was therefore conducted (Table S1 in the Supporting Information). The most appropriate mineralizer was found to consist of 0.5m Na2CO3 and 1.5m NaHCO3 (1:10, w/v; mineralizer A) as: 1) it provides the highest removal efficiency of Cr, and 2) the mineralizer remaining in the supernatant solution can be transformed into essential reagents for industrial recycling (see Supporting Information). Figure 2 shows a comparison of the settling velocity and grain size of three typical samples. The original nanowaste contains a significant amount of lamellar Mg(OH)2 nanocrystals, which do not settle easily from the solution (Figure 2a,d). Hydrothermal coarsening in pure water did not alter the growth and settling velocity of these lamellar nanocrystals appreciably (Figure 2b,e), thereby indicating that the Mg(OH)2 phase in the mud can remain stable on a nanometer scale for extended time periods under naturally occurring conditions. However, after hydrothermal coarsening of the nanowaste with mineralizer A (NaHCO3+Na2CO3), the solids settled to the bottom of the test tube in only 15 min. A subsequent scanning electron microscope (SEM) observation revealed that the nanocrystals had already grown into microsized structures (Figure 2c,f). The amount of chromium remaining in the solid after treatment was determined to be 58, 42, and 0.64%, respectively. Figure 1. Disposal of Cr-containing sludge (I: The conventional process; II: the new route proposed in this study).

Crash restraint air generating inflation system

Abstract: A crash restraint system for an automobile comprising an inflatable bag mounted forward of the automobile passenger seat. A bag inflating device comprising a cluster of gas generating units, each of which has a primary nitrogen generating combustion chamber to produce free nitrogen and other gas products, a second oxygen generating chamber to receive the gas mixture from the first chamber and generate free oxygen and introduce this into the gas mixture, and a tertiary chamber which functions to receive this mixture to react out, filter out and condense out undesired combustion products and also cool the remaining nitrogen-oxygen mixture to provide a ''''breathable air'''' inflating system for the bag. Alternately the first and second zones can be combined into a single nitrogen and oxygen generating zone. In the combustion chamber is a composition made up of an azide (e.g., sodium azide) and an oxidizer (e.g., potassium perchlorate) which upon ignition produces free nitrogen and other combustion products such as sodium oxide, free sodium and potassium chloride. In the second oxygen generating chamber is an oxygen generating composition (e.g., potassium chlorate) that liberates free oxygen into the gaseous mixture from the first combustion chamber. When these first and second zones are combined in a single nitrogen and oxygen generating zone, pellets of the nitrogen generating composition and pellets of the oxygen generating composition are placed together in a single zone or chamber. In the tertiary chamber or zone is a bed of a porous composition (e.g. aluminum oxide granules bonded with boric oxide) that reacts with, condenses and filters out the sodium, sodium oxide and potassium chloride, and permits the free nitrogen and free oxygen mixture to pass therethrough while cooling the same. Thus, the inflating gas mixture is breathable ''''air.

ESR Spectrum of O3− Trapped in a Single Crystal of Potassium Chlorate

Abstract: The O3− radical obtained by x irradiation of oxygen‐17 enriched KClO3 was studied by ESR. The molecule is trapped at three distinct sites in the potassium chlorate single crystal, one of which gives rise to a more intense ESR spectrum. For O3− at the dominant trapping site, the principal values of the g tensor are 2.0035, 2.0187, and 2.0123. Two distinct oxygen‐17 hyperfine splittings were observed and their variation as a function of orientation studied. The principal values of the corresponding hyperfine tensors are 82.6, −8, −8 and 43.6, −5, −5 G. The direction of the maximum principal value for both oxygen‐17 hyperfine tensors coincides with the direction of the minimum principal value of the g tensor, as expected for a bent 19‐electron molecule. The higher splitting is assigned to the central atom and the lower splitting to the magnetically equivalent outer atoms. The spin density distribution in O3− deduced from experimental data is compared with theoretical results obtained from a CNDO/II calculati...