Abstract: A plant and relative controlled production method of monochloramine; inside a reactor, at least a means or group creates and/or maintains a turbulent regime during the production reaction of monochloramine; at the end, at least a post-dosing means performs a further dosage of reagent directly in the concentrated solution of monochloramine produced directly in reactor or on the transfer piping or directly into the storage tank.

Abstract: The present invention relates to a process for reacting chemical compounds comprising the step of reacting a compound of formula (IV) wherein Hal is independently selected from Cl or Br, and X? is a monovalent anion, in the presence of an inorganic acid, wherein the aqueous inorganic acid has a concentration of at least about 60%, at a temperature of about 140° C. to about 250° C., to obtain a compound of formula (V) wherein Hal is as defined above.

Abstract: Method for the production of a coarse-grained ammonium sulphate product by crystallization and installation for carrying out the method. A method for the continuous production of a coarse-grained ammonium sulphate product from an ammonium sulphate solution in a crystallizer operates in accordance with the DTB principle and has an internal suspension circuit and a clarifying zone, from which a clarified partial flow of solution is constantly drawn off into an external circuit, is heated in a heat exchanger so as to dissolve the solids contained therein and is then guided back as a clear solution into the lower region of the crystallizer. In order to ensure production of a product crystallizate with a grain coarseness which is practically constant over time, a fine crystal suspension flow may be drawn off from the clarifying zone as a further partial flow and guided back into the internal circuit of the crystallization stage without any previous dissolution of the solid proportion contained therein.

Abstract: Desirable chemicals are recovered from a raw material that is formed in substantial amounts during the production of cellulose pulp from renewable lingo-cellulose material. An ammonia/ammonium-containing methanol/water mixture is acidified with an acid that has the ability of forming ammonium salt with the ammonium. The mixture is circulated and passed through an apparatus that has an indirect heat exchanger combined with an storage volume fitted with a gas collection device.

Abstract: Fenton and Fenton-like system enhancing agent and the usage thereof are provided. It relates to a water treatment enhancer (enhancing agent) and the usage thereof. It widens water pH range of Fenton and Fenton-like system reaction. It reduces amount of Fe2+ required for Fenton reaction. It increases rate of Fenton-like reaction. The enhancing agent is selected from sodium sulfite, lithium sulfite, potassium sulfite, magnesium sulfite, calcium sulfite, hydroxylamine hydrochloride, hydroxylamine perchlorate, hydroxylamine sulfate, hydrazine, N,N-diethylhydroxylamine, amino ethanolamine, hydroxylamine solution or N,N,N?,N?-tetrasubstituted p-phenylenediamine. The method of use of enhancing agent comprises the steps of: adding Fenton or Fenton-like system enhancing agent, an agent for enhancement and hydrogen peroxide into water subject to treatment; and mixing and allowing reaction. The enhancing agent can increase the rate of reaction for the water treatment and reduce the dosage of the agent for enhancement.

Abstract: The invention relates to a method for preparing pelletized ammonium sulfate particles, the method comprising—providing ammonium sulfate crystals;—isolating a fraction comprising crystals having an intermediate size from crystals having a small size and from crystals having a large size, thereby obtaining remaining crystals comprised of crystals having small size and crystals having large size; and—pelletizing through a die at least part of the remaining crystals, i.e. at least part of the crystals from which the fraction comprising crystals having the intermediate size have been isolated, thereby forming pelletized ammonium sulfate particles.

Abstract: A process for preparing crystalline hydroxylamine-O-sulfonic acid by a. reacting hydroxylamine or a hydroxylammonium salt with oleum/sulfuric acid or with chlorosulfonic acid/sulfuric acid at a temperature in the range from 90 to 130° C., b. continuing to stir the reaction mixture at a temperature in the range from 90 to 130° C. for a period of from 2 to 24 hours, c. cooling the reaction mixture to a temperature in the range from 10 to 40° C. within a period of from 1 to 12 hours and d. subsequently removing and washing the hydroxylamine-O-sulfonic acid which has crystallized out.

Abstract: The present invention relates to a method for potassium or nitrogen based fertilizer production from the byproducts of flue gas processing. Further, the present invention relates to a method for isolating fertilizer precursors from a stream of flue gas. The method including a dry sorbent operation, wet scrubbing operation and an oxidization step to remove air pollutants, a carbon dioxide capture step and a sodium bicarbonate precipitation step. The steps involved in the removal of air pollutants are used to isolate precursors for the production of fertilizer. Additionally, the present invention relates to a method for the removal of carbon dioxide from a flue gas stream.

Abstract: A composition and process for treating sugar solutions that includes one or more sources of ammonium that obtain a pH in water solution above pH 7.0, such as ammonium bicarbonate (NH4HCO3), ammonium phosphate dibasic (NH4)2HPO4, and ammonium sulfite (NH4)2SO3. The composition can also include a particulate sulfur reagent, an amorphous silica, a particulate aluminum reagent, a particulate phosphorous reagent, a particulate filter aid selected from diatomaceous earth and perlite, a particulate activated carbon, a particulate bleaching earth, a polymer decolorant, or combinations thereof. The individual materials can be pre-mixed before addition to the sugar solution, added individually to the sugar solution, or added as a combination of one or more singular ingredients and one or more pre-mixed ingredients.

Abstract: The present invention is directed to the conversion of gas streams comprising ammonia, hydrogen sulfide, and water in the form of liquids or gases that are generated by petroleum refineries and coke ovens to beneficiary agriculture products, by forming ammonium sulfide and then converting the ammonium sulfide, using sulfuric acid, to pure ammonium sulfate.

Abstract: A method and installation for the production of a coarse-grained ammonium sulfate product by crystallization includes firstly generating a crystal having a grain smaller than the desired grain size in a pre-crystallizer and withdrawing a suspension therefrom, from which the fine crystal was previously separated in a classification connecting piece. This suspension, which contains medium-sized grain, is then conducted with a proportion of undersaturated mother liquor, which is sufficient for further crystal growth, into a DTB product crystallizer and crystallized therein to a desired grain size. The heating of the product crystallizer is performed by the heat contained in the vapors of the pre-crystallization. The pre-crystallization may also operate according to the DTB principle, wherein the mother liquor needed for crystallization is supplied in the form of separately admixed concentrated sulfuric acid and ammonia into the external solution loop of the pre-crystallizer.

Abstract: Desirable chemicals are recovered from a raw material that is formed in substantial amounts during the production of cellulose pulp from renewable lingo-cellulose material. An ammonia/ammonium-containing methanol/water mixture is acidified with an acid that has the ability of forming ammonium salt with the ammonium. The mixture is circulated and passed through an apparatus that has an indirect heat exchanger combined with an storage volume fitted with a gas collection device.

Abstract: A method for converting nickel into a nickel salt solution. Nickel is dissolved and reacted in an oxygen-enriched acidic solution to produce a nickel salt solution as illustrated in the following chemical equation, wherein X is a conjugate base: Ni+H2X+½O2->NiX+H2O.

Abstract: A nitrogen oxide purifying apparatus includes a gas absorption vessel (1) and a condenser (6), where the vessel receives an absorption solution containing liquefied N2O4 for absorbing NO and also receives a source gas to vary the temperature and/or pressure of the source gas and the absorption solution, while the condenser receives a gas from the gas absorption vessel (1) to vary the temperature and/or pressure of the gas. In the gas absorption vessel (1), the absorption solution containing liquefied N2O4 may be applied to the source gas containing NO, so that NO is absorbed in the absorption solution. Then the absorption-solution is heated and/or depressurized to generate an intermediate gas containing a relatively large amount of NO and a smaller amount of NO2 from the absorption solution. In the condenser (6), the intermediate gas is cooled and/or pressurized to give condensed N2O3 and/or condensed N2O4.

Abstract: A process for preparing crystalline hydroxylamine-O-sulfonic acid by a. reacting hydroxylamine or a hydroxylammonium salt with oleum/sulfuric acid or with chiorosulfonic acid/sulfuric acid at a temperature in the range from 90 to 130° C., b. continuing to stir the reaction mixture at a temperature in the range from 90 to 130° C. for a period of from 2 to 24 hours, c. cooling the reaction mixture to a temperature in the range from 10 to 40° C. within a period of from 1 to 12 hours and d. subsequently removing and washing the hydroxylamine-O-sulfonic acid which has crystallized out.

Abstract: Process for the production of ammonium thiosulfate from gas streams comprising ammonia and hydrogen sulfide. One embodiment of the invention provides absorbing SO2 into a solution of ammonium sulfite and then contacting gaseous feed streams with portions of the resulting solution in a plurality of contact zones where portions of ammonium sulfite in the liquid streams are converted to ammonium thiosulfate upon contact with the gaseous feed streams.

Abstract: A method of producing hydroxylammonium salts by catalytic reaction of nitrogen monoxide with hydrogen in a diluted aqueous solution of mineral acid in the presence of platinum catalysts suspended on a support in multiple subsequent reaction stages. This reaction takes place in a stirred reactor wherein a gas inlet and distribution system is provided in the lower part of the stirred reactor, a disk agitator is placed immediately above, the hub with bearing surface or support mounting angled, concave and tilted agitator blades that rotate their angled or concave sides in the direction of motion, and a two-blade agitator is provided on the agitator shaft in the upper part of the stirred reactor, its individual leaves being offset like lamellas so that they constantly wet the reactor cap when rotating.

Abstract: Methods of reducing smoke levels in smoke-affected areas, reducing the level of toxic compounds produced by fires, fire suppression, and increasing flame retardancy. In particular, methods according to the present invention comprise dispersing nanocrystalline particles in the areas affected by smoke for sorption of smoke particulates and toxic compounds produced from a fire. The nanocrystalline particles are also effective for use in methods of fire suppression and flame retardancy.

Abstract: Process for the production of ammonium thiosulfate from gas streams comprising ammonia and hydrogen sulfide. One embodiment of the invention provides absorbing SO2 into a solution of ammonium sulfite and then contacting gaseous feed streams with portions of the resulting solution in a plurality of contact zones where portions of ammonium sulfite in the liquid streams are converted to ammonium thiosulfate upon contact with the gaseous feed streams.

Abstract: The present invention provides a reactor for the gas-phase reaction of commercially available gases in the presence of an inert carrier gas to form product gas. The reactor has a streamlined, compact configuration and at least one solids collection and removal system downstream of the reactor, where solids are efficiently removed from the product gas stream, leaving high purity product gas. The removal system allows for a simple reactor design, which is easy to clean and operates continuously over longer periods of time.

Abstract: A process for the continuous preparation of hydroxylammonium salts by catalytic reduction of nitrogen monoxide by means of hydrogen in a dilute aqueous solution of mineral acid in a plurality of reaction stages connected in series comprises dividing the incoming stream of dilute aqueous solution of mineral acid into at least two substreams before it is fed into the plurality of reaction stages connected in series, feeding a first of these substreams to the first reaction stage, feeding a second of these substreams to a reaction stage other than the first, where the inflow of dilute aqueous solution of mineral acid into the plurality of reaction stages connected in series is controlled by means of the pH in this reaction stage other than the first.

Abstract: There is provided an improvement in a process for producing cobalt (III) hexammine sulphate which process comprises oxidatively pressure leaching nickel cobalt sulphides in an ammoniacal ammonium sulphate solution. The nickel and cobalt sulphides are oxidized to sulphates, and an ammoniacal leach liquor in which dissolved cobalt is predominantly in the (III) oxidation state is produced. The ammoniacal leach liquor is combined with ammonia to precipitate the triple salt of cobalt (III) hexammine sulphate, nickel (II) hexammine and ammonium sulphate which is further treated to produce a crystalline cobalt (III) hexammine sulphate and a nickel enriched leach liquor. The improvement involves the provision of a second oxidative pressure treatment effective to maximize the formation of the desired cobalt (III) hexammine ion, prior to the triple salt precipitation step.

Abstract: Process for the separation of a hydroxylammonium salt solution from an aqueous reaction mixture comprising solid catalyst particles by means of filtration, wherein cake filtration through an asymmetric filter is applied, the asymmetric filter comprising at least two layers having different pore diameter, at least one layer being a filter layer, the pore diameter of the filter layer being between 0.1 and 10 &mgr;m and the thickness of the filter layer being 10 to 1000 &mgr;m.

Abstract: The method allows for nickel sulphamate to be produced by means of reacting elementary nickel with sulphamic acid. Therein, the nickel is disintegrated by strong stirring, mixing, or dispersing of the nickel-acid mixture by means of a stirring, mixing, or dispersing tool, introducing high energy density into the reaction mixture. Herein, the nickel is oxidized by reduction of the acid protons of the sulphamic acid without adding special oxidization means. The nickel sulphamate contained in an aqueous solution is especially suitable for electroplating technology since it is for the most part free of foreign ions and amorphous nickel sedimentations.

Abstract: Nitrosylsulphuric acid is mixed in a mixing reactor with sulphuric acid saturated with SO2. The acid mixture is led into a saturating reactor into the bottom region of which water and an SO2-containing gas are introduced. The gas partially serves as stripping gas inside the saturating reactor. SO2-saturated, Nox-free sulphuric acid with 5 to 60 wt % H2SO4 is removed from the bottom region of the saturating reactor and part thereof is mixed with nitrosylsulphuric acid in the mixing reactor.

Abstract: The invention relates to a process for preparing a hydroxylammonium salt through catalytic reduction of nitrate ions in an acid medium in the presence of a palladium and/or platinum catalyst on a carrier in which at least 0.00025 mmol halogen ions are present per m2 of palladium and/or platinum area.

Abstract: The present invention relates to a catalyst based on titanosilicalites having a content by weight of alkali metal or metals of between 0.05 and 2%. The subject of the invention is more particularly a process for producing N,N-disubstituted hydroxylamine from hydrogen peroxide and the corresponding disubstituted amine.

Abstract: A carbon-containing catalyst support is prepared by treating the carbon-containing catalyst support with a compound of the formula IM(OR).sub.m X.sub.n Iwhere M is Ti or Zr, X is Cl or Br, and R is C.sub.1 -C.sub.20 -alkyl, and m and n are integers from zero to four, where the sum of m and n is equal to four.

Abstract: The invention relates to a process for the preparation of a hydroxylammonium salt through catalytic reduction of nitrate ions in an acid medium, in the presence of an activated catalyst, which catalyst comprises carrier particles with a plurality of metal particles containing palladium and platinum, the relative concentrations of the palladium and the platinum in each metal particle being substantially the same. In particular, the distribution of platinum concentrations among different metal particles has a standard deviation of less than 4% absolute.

Abstract: A process for the preparation of hydroxylammonium salts by catalytic reduction of nitrogen monoxide using hydrogen in the presence of a hydrogenation catalyst, comprises(a) in a first step, filtering the reaction mixture obtained after the reaction, giving a solution of essentially hydroxylammonium salt and a filter residue essentially comprising a mixture of hydrogenation catalyst and a solution of essentially hydroxylammonium salt, and(b) in a second step, subjecting the filter residue to a further separation process in order to concentrate the hydrogenation catalyst, giving a mixture having a higher concentration of hydrogenation catalyst than the filter residue and a mixture having a lower concentration of hydrogenation catalyst than the filter residue.

Abstract: Solutions of an hydroxylamine or an at least partially neutralized hydroxylamine salt are stabilized against decomposition by adding thereto a mercaptobenzothiazole, a mercaptothiazoline, a thiuram disulfide, thiourea or a mercaptoalkanol.

Abstract: Exhaust gases containing oxides of nitrogen and sulfur from a fired process heater, a fossil fuel fired boiler, or a chemical process are diverted from a stack prior to admission to the atmosphere through a duct system containing heat exchangers that reduce the exhaust gas from an elevated temperature, if any, to about ambient temperature. Any heat extracted from the exhaust gas may be transferred to the boiler feed water which would serve to reduce the energy cost of operating a boiler. Once the exhaust gas is cooled to about ambient temperature, the gas is then mixed with an oxidant, such as ozone, at a preselected molar ratio to transform the oxides to higher orders of nitrogen and sulfur oxides to increase the absorbability of the nitrogen and sulfur oxides in a reagent solution. The reagent absorbs the oxidized contaminants from the exhaust gas. The oxides are transformed to dilute acids which are then neutralized to form salts that are acceptable for discharge to a municipal waste water treatment plant.

Abstract: A process for the preparation of hydroxylammonium salts by the reduction of nitrogen oxide (NO) with hydrogen in dilute aqueous mineral acid in the presence of a suspended platinum catalyst which is partially poisoned with arsenic, at elevated temperature, wherein the catalyst used is one which has been produced by precipitation of metallic platinum from an aqueous solution on to a suspended support in the presence of an oxidic arsenic compound, by means of a reducing agent.

Abstract: A process for working up aqueous mother liquors containing hydrochloric acid, sulfuric acid and their hydroxylammonium and ammonium salts, entails the mother liquors being intimately mixed with an excess of cyclohexanone based on the content of hydroxylammonium salts, while maintaining a pH of from 3 to 5.5 by adding alkali metal hydroxide solutions, and the cyclohexanone phase which contains cyclohexanone oxime being removed and washed with water until essentially free of chloride.

Abstract: In a process for the production of hydroxylamine disulfonate diammonium salt (DS) comprising feeding an aqueous ammoniuum nitrite solution, SO.sub.2 gas and trim ammonia to a packed column to create a reaction mixture to produce DS; the improvement comprising controlling said process by measuring the pH of the DS product solution stream, comparing said pH with a pre-selected pH value, and adjusting for deviation of pH by adjusting the feed of nitrite solution and measuring the concentration of unreacted nitrite in the DS product solution stream, comparing said concentration with a pre-selected concentration value, and adjusting for deviation of said concentration by adjusting the feed of trim ammonia.

Abstract: Crystalline hydroxylammonium sulfate is prepared by a process which comprises the following steps:(a) Bringing an aqueous solution which contains from 0.02 to 0.3 part by weight of ammonium sulfate and from 0.02 to 0.2 part by weight of sulfuric acid per part by weight of hydroxylammonium sulfate into contact with a basic ion exchanger and obtaining a solution which has a pH of from 3.0 to 4.0,(b) separating off the basic ion exchanger from the aqueous hydroxylammonium sulfate solution,(c) evaporating down the resulting aqueous hydroxylammonium sulfate solution under reduced pressure at <100.degree. C. and obtaining a concentrated hydroxylammonium sulfate solution,(d) crystallizing out not more than 70% by weight of the hydroxylammonium sulfate present in the aqueous solution to give crystalline hydroxylammonium sulfate and a mother liquor, and(e) isolating and crystalline hydroxylammonium sulfate from the mother liquor.

Abstract: In the production of hydroxylamine disulfonate diammonium salt (DS) comprising reacting ammonium nitrite with ammonium bisulfite and sulfur dioxide in an absorption reactor whereby emission gases comprising NO.sub.x, particularly NO, are released as a result of side reactions, the method of treating said emission gases to reduce the concentration of NO comprises adding NO.sub.2 to the emission gases and contacting the mixture of NO.sub.2 and emission gases with an aqueous alkali solution sufficiently to form nitrite and nitrate ions in said alkali solution.

Abstract: A process for producing hydroxylammonium salts of hydrogenating nitrogen monoxide in an acidic medium in the presence of a catalyst which is prepared by subjecting a platinum compound to a first reductive treatment with a thiosulfate or a thiosulfate combined with an alkali metal sulfide in the presence of a catalyst carrier, and a second reductive treatment with a reductant selected from the group consisting of formic acid, hydrogen, hydrazine and sodium borohydride at a temperature of 50.degree. C. to 150.degree. C.

Abstract: Hydroxylammonium salts are prepared by catalytic reduction of nitrogen monoxide with hydrogen in dilute aqueous mineral acids at elevated temperature in the presence of suspended supported platinum catalysts obtainable by precipitating metallic platinum from aqueous solutions of platinum salts onto carriers suspended therein by means of reducing agents in the presence of one or more water-soluble substituted or unsubstituted thioureas.

Abstract: Hydroxylammonium salts are prepared by catalytic reduction of nitrogen monoxide with hydrogen at elevated temperature in a dilute aqueous solution of a mineral acid in the presence, in suspension, of a supported platinum catalyst obtainable by precipitating metallic platinum from an aqueous platinum solution onto a support by means of a reducing agent in the presence of an organic chelating agent and partially poisoned with sulfur.

Abstract: This invention relates to a method for catalyzing the reactionsQZ+H.sub.2 X.fwdarw.QZX (1) psandQZX.fwdarw.QZ+H.sub.2 X (2)wherein Q=C or N;Z=O or S;X=O, S, NH or NR;R=C.sub.1 to C.sub.8 alkyl which may be linear, branched or cyclized,which comprises:contacting at least one polydentate nitrogen-containing chelating agent complexed with a metal atom with the reactants of one of said reactions, wherein said contacting takes place in the presence of a means for oxidizing when reaction (1) is catalyzed and in the presence of a means for reducing when reaction (2) is catalyzed.

Abstract: Hydroxylamine-O-sulfonic acid is prepared by(a) reacting hydroxylammonium sulfate with oleum at elevated temperatures,(b) isolating sulfuric acid from the hydroxylamine-O-sulfonic acid formed,(c) diluting the sulfuric acid which was obtained in stage (b) and which still contains hydroxylamino-O-sulfonic acid with water to 2-6N and heating it to 30.degree.-80.degree. C. for 1-10 hours,(d) preparing hydroxylamine by catalytic reduction of nitrogen monoxide with hydrogen using the dilute sulfuric acid from stage (c) in the presence of a noble metal catalyst at elevated temperatures.

Abstract: An improved process for the continuous preparation of hydroxylammonium salts by catalytic reduction of nitric oxide with hydrogen in a dilute aqueous solution of a mineral acid in the presence of a suspended noble metal catalyst at an elevated temperature in several reaction zones connected in series, wherein the improvement comprises maintaining a pH of <2.0 in the last reaction zone.

Abstract: Hydroxylammonium salts are prepared by an improved process, wherein nitric oxide is reduced catalytically with hydrogen in a dilute aqueous solution of a mineral acid in the presence of a suspended supported platinum catalyst and at elevated temperatures, and wherein the improvement comprises avoiding the formation of foam at the surface of the reaction mixture.

Abstract: A process for the preparation of hydroxylammonium salts by catalytic reduction of nitric oxide with hydrogen in a dilute aqueous solution of a mineral acid, in the presence of a suspended supported platinum catalyst, at elevated temperatures, wherein the reaction is carried out in a conventional manner, in one or more reaction zones, under superatmospheric pressure, and the exit gases produced are let down to a lower pressure, and are reacted, in a downstream reaction zone, with the reaction mixture, containing hydroxylammonium salt, the ammonium salt, the supported platinum catalyst and residual mineral acid, from the upstream reaction zone or zones, or with a fresh aqueous solution of the mineral acid, which contains the supported platinum catalyst in suspension.

Abstract: Ammonium sulfamate is prepared continuously, starting from ammonia and sulfur trioxide, by introducing liquid sulfur trioxide and liquid ammonia in a molar ratio NH.sub.3 /SO.sub.3 greater than 2.0:1 into a pressure reactor containing molten reaction product. Excess ammonia is removed continuously from the reactor. The liquid sulfur trioxide is introduced into the melt, while the liquid ammonia is fed onto the surface of the melt.

Abstract: Ammonium nitrilotrisulfonate is obtained by introducing nitric oxides into an aqueous ammonium sulfite solution at a pH of 5.0-7.5. The solution should contain at least 20 g/l of ammonium nitrilotrisulfonate in suspended form.

Abstract: Ammonium nitrilotrisulfonate can be hydrolyzed, in a solid form or dissolved form, with alkali metal hydroxide to give alkali metal salts of imidodisulfonic acid or a mixture of alkali metal salts of imidodisulfonic acid and nitrilotrisulfonic acid, amidosulfonic acid and sulfuric acid. Ammonium nitrilotrisulfonate is preferably added to an aqueous solution of an alkali metal hydroxide, which contains at least 3 moles of alkali metal hydroxide per mole of ammonium nitrilotrisulfonate to be added.

Abstract: A mixture of ketoxime such as methyl ethyl ketone oxime (MEKO), an inorganic acid such as sulfuric acid and optionally water is fed to an intermediate point of a fractional distillation column. Steam is fed to the base of the column and operating conditions are sufficient to produce the corresponding ketone (e.g. methyl ethyl ketone) or its water azeotrope as the overhead product and the corresponding hydroxylammonium salt (e.g. the sulfate) as the bottoms. Crystallization of the salt from the bottoms leaves a mother liquor which may be recycled to a reboiler from which the steam is generated.

Abstract: A process for the manufacture of ammonium sulfamate by introducing under pressure ammonia and sulfur trioxide into a reactor containing a melt which mainly consists of ammonium sulfamate and ammonium imidodisulfonate, while maintaining a molar ratio of NH.sub.3 /SO.sub.3 of from 1.5 to 1 to 2.0:1, which comprises introducing sulfur trioxide into the gas phase above the melt.