Method for analysis and determination of heavy metal occurrence key mineral phases in industrial solid waste

Patent metadata

Field	Value
Publication number	US-2023117820-A1
Application number	US-202217990501-A
Country	US
Kind code	A1
Filing date	Nov 18, 2022
Priority date	Aug 19, 2021
Publication date	Apr 20, 2023
Grant date	—

Abstract

The present invention provides a method for analysis and determination of the heavy metal occurrence key mineral phases in industrial solid waste, by performing N concentration gradients dissociation determination of the heavy metal solid waste to be tested under the same dissociation conditions, to give the dissociation degrees of the heavy metal elements to be tested at N different concentration gradients; the dissociated solid residues after dissociation being quantitatively analyzed for the mineral phase, to give the relative content of each mineral phase in the M mineral phases of the heavy metal solid waste to be tested; then calculating to give the occurrence distribution proportion of the heavy metal elements in the mineral phase, which are accumulated from high to low; the occurrence key mineral phase whose cumulative occurrence proportion exceeds the preset cumulative threshold value is determined to be the key mineral phase of the heavy metal elements.

First claim

What is claimed is:

1 . A method for analysis and determination of the heavy metal occurrence key mineral phases in industrial solid waste, comprising the following steps:
S1, determining the content of the heavy metal element in the heavy metal solid waste to be tested, to give the content of p kinds of heavy metal elements to be determined in the heavy metal solid waste to be tested; S2, performing n concentration gradients dissociation determination of the heavy metal solid waste to be tested under the same dissociation conditions, to give the dissociation degrees of the heavy metal element to be determined at n different concentration gradients Exp nxp = d 11 ⋯ d 1 p ⋮ d i j ⋮ d n 1 ⋯ d n p wherein the d ij represents the dissociation degree of the heavy metal element j to be determined in the i-th concentration gradient dissociation determination, d ij ∈ (0,1), i=1,2 ,3 ,...,n, j=1,2 ,...,p; S3, quantitatively analyzed the dissociated solid residue after dissociation in step S2 for the mineral phase, to give the relative content W ik of each mineral phase in m mineral phases of the heavy metal solid waste to be tested, and then calculating the dissociation degree of each mineral phase L n x m = 1 11 ⋯ 1 1 m ⋮ 1 i k ⋮ 1 n 1 ⋯ 1 n m according to the formula I i k = m o W o k − m i W i k m o W o k , wherein k=1, 2, 3, ..., m, l ik represents the dissociation degree of the mineral phase k in the i-th concentration gradient dissociation determination, W 0k is the mass fraction of the mineral phase k in the heavy metal solid waste to be tested under the initial conditions, m 0 is the initial sample mass of the heavy metal solid waste to be tested, m i is the mass of the dissociated solid residue after the i-th concentration gradient determination, and W ik is the mass fraction of the mineral phase k in the dissociated solid residue after the i-th concentration gradient determination; S4, according to the formula L nxm × R mxp = Exp nxp , solving the occurrence distribution proportion of the heavy metal element in the mineral phase R m x p = r 11 ⋯ r 1 p ⋮ r k j ⋮ r m 1 ⋯ r m p , r kj ∈ (0,1); and S5, accumulating the occurrence distribution proportions of the heavy metal element j in the mineral phase from high to low, and determining the mineral phase whose cumulative occurrence proportion exceeding the preset cumulative threshold value to be the key mineral phase of the heavy metal element j.

2 . The method according to claim 1 , wherein the calculating formula of the d ij comprises

d

i
j

=

c

i
j

V

i
j

ω

o
j

m
o

,

ω 0j is the mass fraction of the heavy metal element j in the heavy metal solid waste to be tested under the initial conditions, c ij is the concentration of the heavy metal element j in the dissociated solution after the i-th concentration gradient determination, and V ij is the volume of the dissociated solution after the i-th concentration gradient determination.

3 . The method according to claim 2 , wherein before the step S2, it also comprises pre-cleaning the heavy metal solid waste to be tested; wherein the calculating formula of the ω 0j is

ω

0
j

=

ω
j
'

m
a

−

c
j
'

V

m
b

,

ω
j
'

is the mass fraction of the heavy metal element j in the heavy metal solid waste to be tested without pre-cleaning, m a is the mass of the heavy metal solid waste to be tested without pre-cleaning, m b is the mass of the heavy metal solid waste to be tested after pre-cleaning,

c
′

j

is the concentration of the heavy metal element j in the cleaning solution of the heavy metal solid waste to be tested after pre-cleaning, V is the volume of the cleaning solution of the heavy metal solid waste to be tested after pre-cleaning.

4 . The method according to claim 3 , wherein the pre-cleaning steps include: 0.1 mol/L ammonium acetate solution with a pH=7.0 is used as the pre-cleaning reagent, which is mixed with the heavy metal solid waste to be tested at a liquid-solid ratio of 10 L: 1 kg, then oscillated horizontally for 1-2 h at 15-35° C., the obtained solution is centrifuged at 6000 rpm-10000 rpm for 3-10 min to give the cleaning solution and the heavy metal solid waste to be tested after pre-cleaning; the content of the heavy metal elements in the cleaning solution is measured, and the heavy metal solid waste to be tested after pre-cleaning is quantitatively analyzed for the mineral phase.

5 . The method according to claim 1 , wherein before the step S1, it also comprises the step of pretreatment of the heavy metal solid waste to be tested: the sample of the heavy metal solid waste to be tested is air-dried at 60-105° C. and ground to a sample powder with a size below 200 meshes.

6 . The method according to claim 1 , wherein the steps of the determination of n concentration gradients under the same dissociation conditions include: at the same time and under the same outer field effect, the solid waste is nonspecifically dissociated in acid solutions with n concentration gradients, and the content of the heavy metal element in the dissociated solution after dissociation is measured; wherein the a

Assignees

• Univ Central South

Inventors

• Lin Zhang
• Lin Le
• Liang Yanjie
• Liu Xueming
• Ke Yong
• Yan Xu
• Tian Chen
• Liu Zhangbin

Classifications

• G01N2223/0566

  analysing diffraction pattern · CPC title

• G01N2223/605

  phases · CPC title

• G01N23/2055 Primary

  Analysing diffraction patterns · CPC title

• G01N2223/652

  impurities, foreign matter, trace amounts · CPC title

• G01N23/20 Primary

  by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials · CPC title