METHOD AND APPARATUS FOR DRYING METAL FINE PARTICLE, AND METHOD OF PRODUCING NICKEL FINE PARTICLE USING THE SAME

PROBLEM TO BE SOLVED: To provide a drying method capable of drying metal fine particles produced by wet method so as to have a small oxygen content thereof in a short period of time.SOLUTION: A drying method includes: drying metal fine particles in a wet state having a water content of preferably 40 mass% or less, typically represented by nickel fine particles crystallized by wet method and having a mean particle size of not less than 0.05 μm nor more than 0.4 μm, by a standing dryer, band dryer, and spray dryer in an atmosphere of superheated steam of not less than 170°C nor more than 500°C; and cooling the dried metal fine particles with an inert gas or an inert gas containing a reducing gas. 【課題】 湿式法で作製された金属微粒子をその酸素含有量が少なく且つ短時間で乾燥することが可能な乾燥方法を提供する。【解決手段】 湿式法で晶析させた平均粒径０.０５μｍ以上０.４μｍ以下のニッケル微粒子に代表されるような含水率が好ましくは４０質量％以下の湿潤状態の金属微粒子を静置式乾燥装置やバンド型乾燥装置やスプレードライヤー等を用いて１７０℃以上５００℃以下の過熱水蒸気の雰囲気で乾燥させた後、該乾燥後の金属微粒子を不活性ガス、または、還元性ガスを含んだ不活性ガスの雰囲気で冷却する。【選択図】 図２