CN105466916A - Method for rapid combined measurement of lead and zinc in copper smelting soot - Google Patents

Abstract

The present invention relates to a method for rapid combined measurement of lead and zinc in copper smelting soot. The method comprises the steps of: 1) dissolving: weighing a certain amount of copper smelting soot, moistening the soot with water, adding hydrochloric acid according to the weight to volume ratio of soot to hydrochloric acid being 1g / 50ml, heating at 200-300 DEG C for 2-3min, adding nitric acid in the same volume as hydrochloric acid, heating at 200-300 DEG C for 2-3 min; 2) precipitation: sulfuric acid and potassium sulfate for precipitation to obtain lead sulfate; 3) determination of lead; and 4) determination of zinc. The method of the present invention eliminates the interference of impurities, which cannot be eliminated in general lead and zinc combined measurement methods, simplifies the procedures, shortens the analysis time, eliminates the adsorption of zinc ions by the precipitate in the secondary filtration of the zinc detection process (lower zinc content has greater impact), avoids detection by means of equipment, improves the accuracy and efficiency, and reduces the costs.

Description

The method of the quick tie-in of the plumbous zinc of a kind of Copper making cigarette ash

Technical field

The invention belongs to Copper making cigarette ash detection field, particularly relate to the technique of the quick tie-in of the plumbous zinc of a kind of Copper making cigarette ash.

Background technology

Existing copper smelts the chemical analysis method that electric precipitator dusts assay does not have standard, is all generally directly adopt nonferrous metals ore chemical analysis method, as the chemical analysis method (list of references: (1) Peng Ling of Pb-Zn deposits, copper concentrate etc.; Plumbous zinc rapid Continuous Determination in Pb-Zn deposits; Jiangxi nonferrous metal the 24th volume the 1st phase; 2010.3; (2) the large pool of woods; Zhang Yongde; Wu Min; Nonferrous metals ore and select smelting product analysis; Metallurgical industry publishing house; 2007.9).

Because Copper making cigarette ash and Pb-Zn deposits, copper concentrate there are differences on chemical analysis, directly adopting its method to carry out, plumbous zinc detects is existing defects, and arsenic in special Copper making cigarette ash composition, antimony, tin, rapid determination of content of cadmium element are relatively high, and interference analysis result detects.In prior art, in the assay of Copper making cigarette ash, the quick tie-in of plumbous zinc generally adopts the technique of Figure of description 1.This process pilot sample hydrochloric acid, nitric acid dissolve; After precipitation acetic acid-sodium acetate solution dissolves, plumbous with EDTA titration measuring; Filtrate is with EDTA titration measuring zinc.

But above-mentioned technique exists complex operation step, cycle detection time is long, the defects such as inefficiency.

Summary of the invention

The present invention is exactly to overcome the above-mentioned defect existed in prior art, eliminate the indelible impurity interference of general plumbous zinc simultaneous measuring method institute, simplify the operation step, while shortening analysis time, the absorption (when Zn content is lower, impact is larger) on zinc ion is precipitated when eliminating secondary filtration in zinc testing process, avoid and detect by instrument and equipment, the while of improving accuracy and work efficiency, again reduce cost.

The present invention specifically provides following technical scheme:

A method for the quick tie-in of the plumbous zinc of Copper making cigarette ash, is characterized in that, comprise the steps:

1) dissolve:

Weigh a certain amount of Copper making cigarette ash, with water-wet, add hydrochloric acid according to cigarette ash, hydrochloric acid mass volume ratio 1g/50ml, heat 2-3min at 200-300 DEG C after, add the nitric acid with hydrochloric acid same volume, at 200-300 DEG C, heat 2-3min; Described concentration of hydrochloric acid is 12.0mol/L, and concentration of nitric acid is 14.5mol/L;

2) precipitate:

Add the concentrated sulphuric acid according to cigarette ash, hydrochloric acid mass volume ratio 1g/25ml and emit white cigarette, then add the hydrobromic acid with concentrated sulphuric acid same volume, shake up, smolder 3-5 minute, repeatedly processes 2-3 time with the concentrated sulphuric acid of same volume and hydrobromic acid; After cooling, add the potassium sulfate of Copper making cigarette ash quality 2.5 times, heating is boiled to mixing material and is concentrated to 1/2 of original volume; Add the absolute ethyl alcohol of mixing material volume 1/3, place 30-60 minute; With quantitative filter paper filtration at a slow speed; Described concentrated sulphuric acid concentration is 18.4mol/L; Hydrobromic acid concentration is 8.6mol/L;

3) plumbous mensuration:

To the precipitation obtained be filtered, adopt conventional ascorbic acid and xylenol orange indicator, the content of EDTA standard solution titration determination lead;

4) Direct spectrophotometry:

Add screening agent in filtrate after, directly add 25mL acetate-sodium acetate buffer, after stirring, leave standstill 15min, adopt conventional ascorbic acid and xylenol orange indicator, the content of EDTA standard solution titration determination zinc.

Described add in filtrate screening agent operation refer to: in filtrate, add 15-30mL200g/L potassium fluoride solution, under constantly stirring, add ammoniacal liquor be neutralized to the blue Kocide SD of appearance, drip sulfuric acid (sulfuric acid: water volume ratio 1:1) just to disappear and excessive 1 ~ 2 to blueness, add 5-10mL20g/L oxammonium hydrochloride-60g/L thiocarbamide mixed liquor, 2 ~ 3g potassium iodide, stir and make it to dissolve.

Described acetic acid-sodium acetate buffer is that to take 375g anhydrous sodium acetate soluble in water, adds 50mL glacial acetic acid, is diluted with water to 2500mL.

Accompanying drawing explanation

Fig. 1 is the characterization processes process flow diagram of prior art;

Fig. 2 is characterization processes process flow diagram of the present invention;

Embodiment:

Set forth method of the present invention further below in conjunction with concrete operation step, it is pointed out that present embodiment is only set forth the present invention further, is not any restriction.

1, method summary

Eliminate the interference of arsenic, antimony, tin after sample hydrochloric acid, nitric acid dissolve with hydrobromic acid, in Dilute Sulphuric Acid Medium, add potassium sulfate, make potassium sulfate-lead sulfate double salt precipitation that plumbous generation is less than lead sulfate solubleness, filter.After precipitation acetic acid-sodium acetate solution dissolves, plumbous with EDTA titration measuring; While adding the interference of screening agent elimination copper-iron-aluminium plasma in filtrate, add the interference that potassium iodide eliminates cadmium element, then use EDTA titration measuring zinc.This method Zn content more than 1% sample analysis.

2, analytical procedure

Take 0.2000g sample in 250mL beaker, moistening with the water of a small amount of (about 2 ~ 3mL), add 10mL hydrochloric acid, after covering surface plate low temperature (200 ~ 300 DEG C) heating 2 ~ 3min, add 10mL nitric acid, continue heating for dissolving, add 5mL sulfuric acid and emit white cigarette, add 5mL hydrobromic acid, shake up, smolder 3 ~ 5 minutes, repeatedly process 2 ~ 3 (each consumption 5mL, concrete number of processes and consumption are by arsenic in sample, antimony, Theil indices is how many and determine), and continue heating and emit white cigarette 5 minutes, taking off cooling rear is 5% sulfuric acid scrubbing surface plate and walls of beaker by 50mL percent by volume, add the potassium sulfate of 0.5g, heating is boiled and is made volume concentration to about 30mL (concentrating sample solution precursors is long-pending is about 60mL), take off with a small amount of 2% sulfuric acid purge surface plate and wall of cup, in flowing water, cooling adds 10mL absolute ethyl alcohol and continues placement 30 ~ 60min, (at a slow speed: aperture is 1 ~ 3 micron) is filtered with quantitative filter paper at a slow speed, filtrate is collected in 500mL conical beaker, wash beaker with 2% sulfuric acid and precipitate 5 ~ 6 times, finally wash beaker with water and precipitate respectively once, pickling and the liquid after washing all are collected in conical beaker.

The mensuration of 2.1 lead.Precipitation is moved in former beaker together with filter paper, add 30mL acetic acid-sodium acetate buffer along hopper walls and (take 375g anhydrous sodium acetate soluble in water, add 50mL glacial acetic acid, be diluted with water to 2500mL), funnel (about 3 ~ 5mL is rinsed again with water, make the filtrate of noresidue on funnel), cover surface plate, heating is boiled, filter paper is smashed to pieces, stir, insulation 2min, take off with water purge surface plate and wall of cup, 100mL is diluted with water to after cooling, add 2mL200g/L potassium fluoride solution, 0.1g ascorbic acid and 2 (being about 0.5 ~ 1mL) 5g/L xylenol orange indicator, be titrated to claret with the EDTA standard solution of 0.02mol/L and become glassy yellow, be terminal.

Lead content calculates

1. formula $W_{Pb}\%=\frac{C_{EDTA}\×V\×M_{Pb}}{1000\×M}\×100\%$

CEDTA---the volumetric molar concentration of EDTA standard titration solution, mol/L;

V---the volume consumed during EDTA standard titration solution titration lead solution, mL;

MPb---plumbous molal weight, 207.2g/mol;

M---sample mass, g;

2. formula $W_{Pb}\%=\frac{T_{Pb}\×V}{M}\×100\%$

The titer relative to Pb of TPb---EDTA standard titration solution, g/mL;

V---the volume consumed during EDTA standard titration solution titration lead solution, mL;

M---sample mass, g;

2.2 Direct spectrophotometry.15mL200g/L potassium fluoride solution (adding 30mL during iron content height) is added in filtrate, under constantly stirring, add ammoniacal liquor be neutralized to the blue Kocide SD of appearance, drip sulfuric acid (volume ratio 1+1) just to disappear and excessive 1 ~ 2 to blueness, add 5mL20g/L oxammonium hydrochloride-60g/L thiocarbamide mixed liquor (adding 10mL during Fe content height), 2 ~ 3g potassium iodide (stirring makes it to dissolve), 25mL acetate-sodium acetate buffer (the same), 15min is left standstill after stirring, add 0.1g ascorbic acid and 2 (being about 0.5 ~ 1mL) 5g/L xylenol orange indicator, be titrated to claret with 0.02mol/LEDTA standard solution and become glassy yellow, be terminal.

Zn content calculates

1. formula $W_{Zn}\%=\frac{C_{EDTA}\×V\×M_{Zn}}{1000\×M}\×100\%$

C _eDTA---the volumetric molar concentration of EDTA standard titration solution, mol/L;

V---the volume consumed during EDTA standard titration solution titration zinc solution, mL;

M _zn---zinc molal weight, 65g/mol;

M---sample mass, g;

2. formula $W_{Zn}\%=\frac{T_{Zn}\×V}{M}\×100\%$

T _zn---the titer relative to Zn of EDTA standard titration solution, g/mL;

V---the volume consumed during EDTA standard titration solution titration zinc solution, mL;

M---sample mass, g;

3, test and checking

The selection of acidity when 3.1, measuring:

Measure plumbous acidity (mass percent of sulfuric acid in sample solution) to select: it is 15% ~ 60% that lead sulfate precipitates optimum acidity, this test selective precipitation acidity 20% ~ 25% (operates according to the method described above, according to the sulfuric acid content of solution during through repeatedly measuring its plumbous precipitation operation, thus sour addition in adjustment process, to smolder the time, reach the object controlling sulfuric acid content.After method maturation, will sulfuric acid content do not measured in the testing process of lead).The acidity measuring zinc is selected: when measuring zinc, PH is lower than 5.8, terminal is spun out, PH produces closed phenomenon when being greater than 6.0, control PH=5.8 ~ 6.0 (operate by this method according to the method described above, according to the PH of liquid to be measured during through repeatedly measuring zinc titration operation, thus sour, alkali addition in adjustment process, reach control PH object.After method maturation, will PH do not measured in the testing process of zinc).

3.2, the elimination of disturbing factor:

3.2.1, adopt trisalt acid, nitric acid, sulfuric acid decomposition sample, utilize hydrobromic acid to eliminate the interference of arsenic, antimony, tin.

3.2.2 potassium fluoride, ascorbic acid, thiocarbamide, is utilized to shelter the interference such as aluminium, iron, copper.

3.2.3, EDTA complexometry zinc time, usually record zinc, cadmium total amount, then deduct Atomic absorption and record cadmium content and obtain actual Zn content, this method potassium iodide shelters cadmium, directly can measure zinc.

4, analysis result contrast: this test will randomly draw 4 our factory Copper making electric precipitator dusts samples, measure Pb, Zn content by plumbous zinc tie-in method, atomic absorption analysis method after plumbous zinc tie-in method, improvement before improvement respectively, carry out the contrast of reappearance, accuracy.

Table one Determination of Pb reappearance contrasts

Table two zinc-content determination reappearance contrasts

Table three accuracy is compared

5, the result

5.1 utilize sulfuric acid, potassium sulfate to precipitate lead, generate potassium sulfate-lead sulfate double salt precipitation that solubleness is less, improve the recovery of the lead in testing process.

5.2 this method eliminate, and secondary filtration when zinc measures, regulate the tedious steps of PH, Instrument measuring cadmium content, and single sample shortens 1 ~ 2 hour detection time.And decrease the use of medicament, the energy, instrument, reduce testing cost.

From table one, two, three, 5.3 can find out that this assay method reappearance, accuracy are all good than detection method before improvement.

Stablized by verification experimental verification this method measurement result, favorable reproducibility, accuracy are high, and method step is simple, greatly shorten analysis time, improve work efficiency, reduce assay cost, can apply in the express-analysis of the Pb, Zn content of Copper making cigarette ash completely.

Claims (3)

1. a method for the quick tie-in of the plumbous zinc of Copper making cigarette ash, is characterized in that, comprise the steps:

1) dissolve:

Weigh a certain amount of Copper making cigarette ash, with water-wet, add hydrochloric acid according to cigarette ash, hydrochloric acid mass volume ratio 1g/50ml, heat 2-3min at 200-300 DEG C after, add the nitric acid with hydrochloric acid same volume, at 200-300 DEG C, heat 2-3min; Described concentration of hydrochloric acid is 12.0mol/L, and concentration of nitric acid is 14.5mol/L;

2) precipitate:

Add the concentrated sulphuric acid according to cigarette ash, hydrochloric acid mass volume ratio 1g/25ml and emit white cigarette, then add the hydrobromic acid with concentrated sulphuric acid same volume, shake up, smolder 3-5 minute, repeatedly processes 2-3 time with the concentrated sulphuric acid of same volume and hydrobromic acid; After cooling, add the potassium sulfate of Copper making cigarette ash quality 2.5 times, heating is boiled to mixing material and is concentrated to 1/2 of original volume; Add the absolute ethyl alcohol of mixing material volume 1/3, place 30-60 minute; With quantitative filter paper filtration at a slow speed; Described concentrated sulphuric acid concentration is 18.4mol/L; Hydrobromic acid concentration is 8.6mol/L;

3) plumbous mensuration:

To the precipitation obtained be filtered, adopt conventional ascorbic acid and xylenol orange indicator, the content of EDTA standard solution titration determination lead;

4) Direct spectrophotometry:

Add screening agent in filtrate after, directly add 25mL acetate-sodium acetate buffer, after stirring, leave standstill 15min, adopt conventional ascorbic acid and xylenol orange indicator, the content of EDTA standard solution titration determination zinc.

2. the method for the quick tie-in of the plumbous zinc of Copper making cigarette ash as claimed in claim 1, it is characterized in that, described add in filtrate screening agent operation refer to: in filtrate, add 15-30mL200g/L potassium fluoride solution, under constantly stirring, add ammoniacal liquor be neutralized to the blue Kocide SD of appearance, drip sulfuric acid (sulfuric acid: water volume ratio 1:1) just to disappear and excessive 1 ~ 2 to blueness, add 5-10mL20g/L oxammonium hydrochloride-60g/L thiocarbamide mixed liquor, 2 ~ 3g potassium iodide, stir and make it to dissolve.

3. the method for the quick tie-in of the plumbous zinc of Copper making cigarette ash as claimed in claim 1, is characterized in that, described acetic acid-sodium acetate buffer is that to take 375g anhydrous sodium acetate soluble in water, adds 50mL glacial acetic acid, is diluted with water to 2500mL.