CN102128803B

CN102128803B - Method for measuring silicon content in papermaking black liquor quickly

Info

Publication number: CN102128803B
Application number: CN 201010607989
Authority: CN
Inventors: 刘梦茹; 乔军; 应广东; 钟洪霞
Original assignee: SHANDONG TAIYANG PAPER INDUSTRY Co Ltd
Current assignee: SHANDONG TAIYANG PAPER INDUSTRY Co Ltd
Priority date: 2010-12-28
Filing date: 2010-12-28
Publication date: 2013-01-02
Anticipated expiration: 2030-12-28
Also published as: CN102128803A

Abstract

The invention relates to a method for measuring silicon content, in particular to a method for measuring silicon content in papermaking black liquor quickly, which comprises the following steps of: a, preparing standard solution; b, establishing a standard curve; c, processing a black liquor sample by solution of H2O2, concentrated nitric acid and sodium hydroxide; d, detecting the sample; and e, calculating a result. The method has the advantages that: the measurement of the silicon content in the black liquor by the method is very accurate, convenient and quick; the method is suitable for batch measuring in experiments; and the reagents are common, so the cost of the experiments is low.

Description

A kind of method of Fast Measurement silicon content in papermaking black liquor

Technical field

The present invention relates to a kind of method of measuring silicone content, be specifically related to a kind of method of Fast Measurement silicon content in papermaking black liquor.

Background technology

Alkali in the pulp and paper industry reclaims for reducing paper-making black liquor, protection of the environment and economizing on resources and the energy, realizes that the Significance of Sustainable Development of paper industry is great.Although the existing very ripe alkali recovery technology of black liquor of at present pulping wood being discharged is relatively more difficult to the alkali recovery of Black liquor from straw pulping process.Why difficult straw pulp black liquor is, just is that its silicone content is higher.How to reduce silicone content, become the key of straw pulping black liquor, people just are being devoted to research and develop the various silicon technologies that fall, such as carbon dioxide process, lime method, magnesium sulphate method etc.In these researchs, crucial part is to measure like clockwork the silicone content in the research object.

The assay method of silicone content is a lot, mainly contains: wave arching pushing, volumetric method, gravimetric method and colourimetry etc.For high silicon (Si 〉=0.4%) sample tests, generally adopt the gravimetric determination silicone content.In long-term use procedure, the method exposes some obvious drawbacks gradually: (1) is very high to Test Condition Requirements; (2) complex operation step is bothersome, consuming time oversize, and numerous and diverse operation is easy to bring larger error at measurment; (3) the method does not adopt the silicon standard reagent to compare, and causes the operator to be unable to estimate the error that assay method brings.In addition, about the mensuration of silicone content in black liquor and the paper pulp, there is no at present national standard or industry standard method.The assay method of silicon is the important means that black liquid is processed in research in black liquor and the paper pulp, along with the progress of paper technology, must find out the method for silicone content in a kind of Fast Measurement black liquor and the paper pulp.

Summary of the invention

In order to solve above-mentioned technical matters, the invention provides the method for a kind of accuracy height, energy Fast Measurement silicon content in papermaking black liquor.

The present invention realizes that by following technical proposals the principle of the method for a kind of Fast Measurement silicon content in papermaking black liquor of the present invention is as follows:

The black liquor sample transfers silicon wherein to the silicate of solubility after treatment.In nitric acid medium, with excessive potassium ion, fluorine ion effect, generate quantitatively potassium fluosilicate (K ₂SiF ₆) precipitation.Reaction equation is as follows:

SiO ^2- ₃+6F ^-+6H ⁺+2K ⁺?→?K ₂SiF ₆↓+3H ₂O

Concrete grammar comprises following step:

A. preparing standard solution;

B. build typical curve;

C. adopt H ₂O _2,Red fuming nitric acid (RFNA) and sodium hydroxide solution are processed the black liquor sample;

D. test sample;

E. result of calculation.

The concrete steps of above-mentioned preparing standard solution are: take by weighing Na ₂SiO ₃9H ₂O, with deionized water dissolving and be settled to 100mL, the storing solution that obtains is deposited in the plastic bottle for subsequent use; Take by weighing the KF solid and join in the 100mL volumetric flask, the deionized water that adds 30mL makes its dissolving, adds dense HNO again ₃, then add entry, continue to add the KCl solid to saturated, get filtrate after the filtration.

The concrete steps of building typical curve among the step b are: in different concentration silicon standard solution, add and carry out the ultraviolet spectrum detection in nitric acid-potassium fluoride solution, obtain respectively them in the ultraviolet absorptivity value at 600nm place, again take the concentration of reacting silicon in the rear sample bottle as horizontal ordinate, take resulting corresponding ultraviolet absorptivity value as ordinate, the drawing standard curve.

The concrete steps of processing the black liquor sample among the step c are: take by weighing the black liquor sample in beaker, then add H ₂O ₂, boil, in heating process, add appropriate amount of purified water, then add red fuming nitric acid (RFNA), boil cooling, add sodium hydroxide solution and make silicon in the solution be converted into the silicate of dissolving, at last with the solution constant volume.

The concrete steps of above-mentioned test sample are: measure the black liquor sample, it is added nitric acid-potassium fluoride solution, carry out ultraviolet spectrum after the mixing and detect, according to the absorbance at record 600nm place.

With the typical curve among the absorbance substitution step b that measures in the described steps d, by calculating the content of silicon in the black liquor.

Beneficial effect of the present invention is, adopted above-mentioned method to measure the content of silicon in the black liquor, and accuracy is high, and batch convenient and swift, that be fit in the experiment is measured, and above-mentioned reagent is all comparatively common, and therefore should experiment spent cost is lower.

Embodiment

Below in conjunction with embodiment the present invention is further described, so that those skilled in the art understands the present invention more fully.

(1) solution preparation

1. prepare silicon standard solution

Accurately take by weighing 1.0119g Na ₂SiO ₃9H ₂O with deionized water dissolving and be settled in the 100mL volumetric flask, must contain the Si(IV) the 1.000g/L storing solution, be stored in the plastic bottle for subsequent use.

2. prepare nitric acid-potassium fluoride solution

Take by weighing KF solid 15g and add in the 100mL volumetric flask, be dissolved in the deionized water of 30mL, then add dense HNO ₃Then 20mL adds entry 50mL, continues to add the KCl solid to saturated, gets filtrate after the filtration.

(2) Criterion curve

The concentration that accurately adds respectively different amounts (0～1000 μ L) in one group of polyethylene bottle is 1.000g/L silicon standard solution, then adding a certain amount of nitric acid-potassium fluoride solution makes cumulative volume reach 5mL, use immediately manual time-keeping, behind the 5min, strongly shaking the bottle of level, and solution transferred to carry out ultraviolet spectrum in the plastics cuvette and detect, obtain respectively them in the ultraviolet absorptivity value at 600nm place.Again take the concentration of reacting silicon in the rear sample bottle as horizontal ordinate, take resulting corresponding ultraviolet absorptivity value as ordinate, the drawing standard curve.

(3) black liquor sample preparation

Accurately take by weighing the black liquor sample of 1.0g in beaker, then add the H of 30 mL30 % ₂O ₂, boil a period of time at electric hot plate.In heating process, add appropriate amount of purified water in order to avoid boil dry.Then add red fuming nitric acid (RFNA) 5mL, boil cooling.Add an amount of sodium hydroxide solution and make silicon in the solution be converted into the silicate of dissolving, at last with the solution constant volume.

(4) sample detection

The black liquor sample of 1. accurately measuring after a certain amount of processing adds in the polyethylene bottle;

2. then add nitric acid-potassium fluoride solution, make cumulative volume reach 5mL;

3. use immediately manual time-keeping;

4. behind the 5min, strongly the shaking the bottle of level, and solution transferred to carry out ultraviolet spectrum in the plastics cuvette and detect;

5. record the ultraviolet absorptivity value at 600nm place.

(5) result calculates

In absorbance substitution step (2) the Plays curve of measuring in the step (4), by calculating the content that can obtain silicon in the black liquor.

Experimental result:

Carry out sample configuration and spectroscopic assay according to experiment condition, and calculate the content of silicon, carry out replication 4 times.Its repeatable experimental result shows that the relative standard deviation of the method is 0.7%.

The accuracy that table 1 method is measured

Numbering	Measure the quality (mg) of silicon	The quality (mg) that silicon adds	The recovery (%)
				1	0.099	0.100	99
2	0.197	0.200	98.5
				3	0.303	0.300	101
4	0.398	0.400	99.5

Claims

1. the method for a Fast Measurement silicon content in papermaking black liquor comprises following step:

A. preparing standard solution: the concrete steps of described preparing standard solution are to take by weighing Na ₂SiO ₃9H ₂O, with deionized water dissolving and be settled to 100mL, the storing solution that obtains is deposited in the plastic bottle for subsequent use; Take by weighing the KF solid and join in the 100mL volumetric flask, the deionized water that adds 30mL makes its dissolving, adds dense HNO again ₃, then add entry, continue to add the KCl solid to saturated, get filtrate after the filtration;

B. build typical curve: the concrete steps of building typical curve are, in variable concentrations silicon standard solution, add and carry out the ultraviolet spectrum detection in nitric acid-potassium fluoride solution, obtain respectively them in the ultraviolet absorptivity value at 600nm place, again take the concentration of reacting silicon in the rear sample bottle as horizontal ordinate, take resulting corresponding ultraviolet absorptivity value as ordinate, the drawing standard curve;

C. adopt H ₂O ₂, red fuming nitric acid (RFNA) and sodium hydroxide solution process the black liquor sample: the concrete steps of processing the black liquor sample are, take by weighing the black liquor sample in beaker, then add H ₂O ₂, boil, in heating process, add appropriate amount of purified water, then add red fuming nitric acid (RFNA), boil cooling, add sodium hydroxide solution and make silicon in the solution be converted into the silicate of dissolving, at last with the solution constant volume;

D. test sample: the concrete steps of described test sample are: measure the black liquor sample, it is added nitric acid-potassium fluoride solution, carry out ultraviolet spectrum after the mixing and detect, according to the absorbance at record 600nm place;

E. result of calculation: with the typical curve among the absorbance substitution step b that measures in the described steps d, by calculating the content of silicon in the black liquor.