# US 2016/0257566 A1 · Method and apparatus for producing compound powders > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0257566 A1 - Document ID: US20160257566A1 - Status: Published application - Kind: A1 - Application number: 15/132,070 - Filed: 2016-04-18 - Published: 2016-09-08 - Earliest claimed: 2012-03-07 - Assignees: Bo Liu; Hongjie Qiu - Applicants: Qualmat, Inc. - Inventors: Bo LIU; Hongjie QIU - Web page: https://patentgrep.com/patent/US20160257566A1 ## CPC - C01B 6/24: Hydrides containing at least two metals; Addition complexes thereof (C01B6/13 - C01B6/23 take precedence) - B22F 9/08: by casting, e.g. through sieves or in water, by atomising or spraying (using electric discharge B22F9/14) - C01B 6/00: Hydrides of metals {including fully or partially hydrided metals, alloys or intermetallic compounds (use of some thereof for reversible sorption of hydrogen C01B3/0005, C01B3/508); Compounds containing at least one metal-hydrogen bond, e.g. (GeH3)2S, SiH GeH}; Monoborane or diborane; Addition complexes thereof (higher hydrides of boron, substituted hydrides of boron C01B35/00) - C01B 9/00: General methods of preparing halides (particular individual halides, see the relevant groups in C01B - C01G according to the element combined with the halogen; electrolytic production of inorganic compounds C25B) - C01B 13/326: {of elements or compounds in the liquid state} - C01B 17/20: Methods for preparing sulfides or polysulfides, in general (ammonium sulfides or polysulfides C01C; sulfides or polysulfides of metals, other than alkali metals, magnesium, calcium, strontium and barium, see the relevant groups of subclasses C01F or C01G, according to the metal) - C01B 21/06: Binary compounds of nitrogen with metals, with silicon, or with boron, {or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron}(azides C01B21/08) - C01B 21/0602: {with two or more other elements chosen from metals, silicon or boron} - B22F 2009/0824: {with a specific atomising fluid} - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER ## Abstract A gas atomization apparatus is disclosed for producing high purity fine refractory compound powders. After the system reaches high vacuum, a first stage inert atomizing gas breaks superheated metal melt into droplets and a second stage reactive atomizing gas breaks the droplets further into ultrafine droplets while reacts with them to form refractory compound powders. The first stage atomizing gas is inert gas able to break up melt into droplets and prevent crust formation on the nozzle front. A reaction time enhancer is arranged at bottom of reaction chamber to furnish a reactive gas flow in a reverse direction of the falling droplets and powders. Under the reverse gas flow, the falling droplets and powders change moving direction and travel longer distance in reaction chamber to increase reaction time. This apparatus can produce refractory powders with ultrahigh purity and uniform powder size while maintain high process energy efficiency. ## Claims ### Claim 1 A method for producing non-metallic, refractory compound powder, the method comprising: providing a metal to a first stage of an apparatus; superheating, by a heating mechanism in the first stage of the apparatus, the metal to a temperature that is higher than a melting point of the metal; supplying an inert gas in the first stage of the apparatus in a way that reduces a probability of a reactive gas inflowing from a second stage of the apparatus into the first stage of the apparatus; receiving, in the second stage of the apparatus, the superheated metal in a first direction; and supplying, in the second stage of the apparatus, the reactive gas to (1) atomize the superheated metal into liquid droplets, and (2) react with the liquid droplets so as to form the non-metallic, refractory compound powder, wherein, in an extension of the second stage of the apparatus, at least a portion of the reactive gas is supplied in a second direction that is different than the first direction so as to change a falling direction of the liquid droplets and increase a reaction time available for the liquid droplets and the reactive gas to form the non-metallic, refractory compound powder in the second stage of the apparatus. ### Claim 2 (depends on 1) The method of claim 1, wherein the second direction is substantially opposite to the first direction. ### Claim 3 (depends on 1) The method of claim 1, further comprising: monitoring a temperature and a pressure of the second stage of the apparatus; and selectively diluting the reactive gas with the inert gas or another gas based on the monitored temperature and pressure of the second stage of the apparatus. ### Claim 4 (depends on 3) The method of claim 3, wherein selectively diluting the reactive gas comprises adjusting a flow rate of the reactive gas and a flow rate of the inert gas or another gas. ### Claim 5 (depends on 1) The method of claim 1, further comprising: cooling, by supplying a coolant at an output of the second stage, the formed non-metallic, refractory compound powder to reduce powder agglomeration. ### Claim 6 (depends on 1) The method of claim 1, further comprising: categorizing the formed non-metallic, refractory compound powder based on the powder's size using one or more cyclone powder collectors. ### Claim 7 (depends on 6) The method of claim 6, further comprising: cleaning, by using a wet scrubber, residual gas at an output of the one or more cyclone powder collectors. ### Claim 8 (depends on 1) The method of claim 1, further comprising: adjusting a nozzle that is responsible for supplying the reactive gas in the second direction so as to change a size of the non-metallic, refractory compound powder formed in the second stage of the apparatus. ### Claim 9 (depends on 1) The method of claim 1, further comprising: pumping the first and second stages of the apparatus to a vacuum state before providing the metal to the first stage of the apparatus. ### Claim 10 (depends on 1) The method of claim 1, wherein providing the metal comprises feeding at least two wires of the same metal into the first stage of the apparatus. ### Claim 11 (depends on 1) The method of claim 1, wherein providing the metal comprises feeding at least two wires of different metals into the first stage of the apparatus. ### Claim 12 (depends on 1) The method of claim 1, wherein providing the metal comprises feeding at least two wires into the first stage of the apparatus, and wherein superheating the metal comprises supplying a voltage bias between the at least two wires. ### Claim 13 (depends on 12) The method of claim 12, wherein the voltage bias creates an electric arc in the first stage of the apparatus. ### Claim 14 (depends on 12) The method of claim 12, wherein the voltage bias comprises a direct current (DC) voltage or a power pulse. ### Claim 15 (depends on 1) The method of claim 1, wherein an average diameter of the liquid droplets is below 300 micrometers. ### Claim 16 (depends on 1) The method of claim 1, wherein a cooling rate for the liquid droplets is greater than 100 K per second. ### Claim 17 (depends on 1) The method of claim 1, wherein the reactive gas comprises one or more of: N2, NH3, or O2. ### Claim 18 (depends on 1) The method of claim 1, wherein non-metallic, refractory compound powder comprises one or more of: metal oxide, hydride, nitride, halide, or sulfide. ### Claim 19 (depends on 1) The method of claim 1, wherein the metal is an alloy. ### Claim 20 (depends on 1) The method of claim 1, wherein the metal is a pure metal.