Patent ID: 11866341
Assignee: DALIAN MINZU UNIVERSITY
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 0:
1. An environmentally friendly large-scale preparation method of fluoride nanomaterial, wherein the fluoride is MF2, REF3 or compound fluoride; the compound fluoride is one or more than one of AMF3, AREF4, A2REF5, A3REF6, ARE2F7, A2RE2F8, ARE3F10, ARE7F22, A5RE9F32, MREF5, M2REF7, MRE2F8, MRE4F14 or REOF; M is one or more than one of Be, Mg, Ca, Sr, Ba, Zn, Cd or Mn; RE is one or more than one of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc, Al, Ga or Bi; A is one or more than one of Li, Na, K, Rb or Cs, wherein the method comprises the following specific preparation steps:
step 1: taking oxide, carbonate, basic carbonate or hydroxide containing M and/or RE as raw material; adding volatile acid a to the raw material; or directly taking volatile acid salt containing M and/or RE as raw material; heating to reflux to dissolve the raw material; and converting the raw material into water-soluble salt to obtain a water-soluble salt solution b; filtering precipitates which may exist in the solution;
step 2: conducting an evaporation process on the water-soluble salt solution b in step 1 to evaporate excess volatile acid a and water which do not participate in the reaction, wherein evaporation temperature is 50-130° C. and relative vacuum is −(0.01-0.09) MPa; then, adding oily organic matter c with high boiling point to continue evaporation under reduced pressure; replacing the volatile acid bound with M and/or RE, wherein evaporation temperature is 80-160° C. and vacuum is 1-3000 Pa; converting all the water-soluble salt b into oil-soluble precursor salt to obtain an oil-soluble salt solution d;
step 3: adding oil-infiltrating fluorine source e to the oil-soluble salt solution d obtained in step 2; when the product is compound fluoride, adding an oil-infiltrating compound of A; conducting a heating reaction at a temperature not higher than 80° C. to generate nanofluoride; then heating and crystallizing the nanofluoride under the protection of inert gas at heating temperature of 180-330° C. and reaction time of 0.5-5 h; after cooling, centrifuging and washing the product; and separating the product of fluoride nanoparticles from the oily organic matter c with high boiling point;
step 4: collecting the evaporated volatile acid a in step 2 for use in the acid dissolution process of step 1;
step 5: collecting the oily organic matter c with high boiling point in step 3 for use in the reduced pressure evaporation process of step 2.