CN211402282U

CN211402282U - Cement chloride ion titration device

Info

Publication number: CN211402282U
Application number: CN201922387651.1U
Authority: CN
Inventors: 高奇; 黄友芬; 蒲晓鹏; ***; 李伟; 吴成慧; 肖映灼
Original assignee: Sichuan Cnec Arct Engineering Testing Co ltd; China Nuclear Industry 24 Construction Co Ltd
Current assignee: Sichuan Cnec Arct Engineering Testing Co ltd; China Nuclear Industry 24 Construction Co Ltd
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2020-09-01
Anticipated expiration: 2029-12-25

Abstract

The utility model discloses a cement chloride ion titration apparatus, which comprises a volumetric flask, a digital display titrator, a magnetic stirrer and a porcelain crucible arranged on the magnetic stirrer, wherein a liquid inlet pipe of the digital display titrator is inserted into the volumetric flask, and a liquid outlet pipe of the digital display titrator is positioned above the porcelain crucible; the device also comprises an optical filter positioned between the porcelain crucible and the observation direction. An object of the utility model is to provide a cement chloride ion titration outfit to there is the problem of titrating the terminal point and judging the difficulty when solving ammonium thiocyanate volumetric method titration cement chloride ion content among the prior art, realize improving titration accuracy and reliability, reduce the purpose of titrating the error.

Description

Cement chloride ion titration device

Technical Field

The utility model relates to a cement detection area, concretely relates to cement chloride ion titration outfit.

Background

The chloride ions in the cement are one of the main sources of the chloride ions in the concrete, and can damage a compact 'passivation protective film' generated on the surface of the steel bar under the strong alkaline condition, so that the steel bar is corroded, and the durability of the concrete structure is damaged. Therefore, the building material industry pays more attention to the control of the content of chloride ions in cement. The cement standard of China stipulates that the content of chloride ions in the cement is not more than 0.06 percent. The method for measuring the content of chloride ions related to the current standard mainly comprises an ammonium thiocyanate volumetric method, a potentiometric method, a mercuric thiocyanate colorimetric method, a phosphoric acid distillation-mercury salt titration method and the like. The ammonium thiocyanate volumetric method is used as a classical precipitation titration method in analytical chemistry, and is also selected as a reference method in a cement chemistry analytical method (GB/T176-.

However, the ammonium thiocyanate volumetric method also has the defect that the method is not negligible, wherein accurate determination of the titration end point causes great trouble to testers and is one of the important factors which mainly influence the analysis and determination results. The concrete expression is as follows: the ferric ammonium sulfate aqueous solution is reddish brown as the indicator of chloride ion content in cement is surveyed to ammonium thiocyanate volumetric method, and can bring the continuous deepening of solution color along with the silver thiocyanate precipitation volume increase that generates, causes the reddish brown who produces behind the ammonium thiocyanate standard titration solution to change unobviously, causes the judgement inaccuracy of titration terminal, brings the error for the test result.

Many experts and scholars have proposed solutions to this problem, such as performing color comparisons in multiple blank tests, performing strict theoretical calculations to control the titration process, or adding corresponding solvents to amplify the color change effect, etc., because these methods involve complicated steps, they have high requirements on the theoretical knowledge level and operation experience of the operator, and are not suitable for wide popularization.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a cement chloride ion titration outfit to there is the problem of titrating the terminal point and judging the difficulty when solving ammonium thiocyanate volumetric method titration cement chloride ion content among the prior art, realize improving titration accuracy and reliability, reduce the purpose of titrating the error.

The utility model discloses a following technical scheme realizes:

a cement chloride ion titration device comprises a volumetric flask, a digital display titrator, a magnetic stirrer and a ceramic crucible arranged on the magnetic stirrer, wherein a liquid inlet pipe of the digital display titrator is inserted into the volumetric flask, and a liquid outlet pipe of the digital display titrator is positioned above the ceramic crucible; the device also comprises an optical filter positioned between the porcelain crucible and the observation direction.

Aiming at the problem that the titration end point is difficult to judge when the ammonium thiocyanate content is titrated by a volumetric method in the prior art, the utility model provides a cement chloride ion titration device, which uses a volumetric flask to prepare liquid, uses a digital display titrator to titrate, uses a ceramic crucible as a titration container, namely uses the ceramic crucible as a container for holding the titrated solution; and stirred by a magnetic stirrer. The optical filter is the prior art in the titration field and is used for staff to observe and determine the titration endpoint. The existing device for titrating the content of chloride ions in cement by using an ammonium thiocyanate volumetric method uses an acid burette for titration, a titration container is a conical flask, and then the mixture is manually stirred by a glass rod. On the basis of the existing ammonium thiocyanate volumetric method, the acid burette is replaced by the digital display titrator, so that the titration accuracy can be improved, and the human error can be reduced; the conical flask is replaced by a porcelain crucible as a container for holding the titrated solution, under the white background of the porcelain crucible, the interference of white silver thiocyanate flocculent precipitate generated by back titration of excessive silver ions by ammonium thiocyanate on the color change in the titration process is obviously reduced, the color change process of the indicator ammonium ferric sulfate solution is obvious, the defects of difficult titration end point judgment, sample waste caused by excessive titration, inaccurate detection result and the like are effectively overcome, and the accuracy and reliability of the method are improved; the stirring of the glass rod is changed into a magnetic stirrer, so that the titration solution can be quickly and uniformly diffused, and the titration end point is not accurately judged due to the fact that the concentration is concentrated and too high. The digital display titrator and the magnetic stirrer in the application can all use the existing finished products.

Furthermore, the bottleneck of volumetric flask sets up the bottle plug, sets up the through-hole that is used for the feed liquor pipe to pass on the bottle plug. The bottle stopper is used for plugging the bottle mouth of the volumetric flask, so that the volatilization of the prepared liquid is avoided, and the pollution of external impurities is also avoided.

Furthermore, a support is arranged on the magnetic stirrer, and the optical filter is arranged on the support. In the prior art, a user holds an optical filter to observe a titration process, and the user needs to control the titration amount on one hand and hold the optical filter on the other hand, so that the operation is inconvenient. For this reason, this scheme sets up the support on magnetic stirrers, places the light filter through the support to reduce the operation degree of difficulty of this application, ensure that the staff all concentrates on the judgement of titrating the terminal point with energy.

Further, a clamp is arranged on the support and used for clamping the optical filter. The optical filter can be clamped by any existing clamp, and the optical filter is only required to be positioned between the observation direction of a worker and the porcelain crucible.

Compared with the prior art, the utility model, following advantage and beneficial effect have:

1. the utility model relates to a cement chloride ion titration outfit can improve and titrate the accuracy, reduces human error in comparison in prior art.

2. The utility model relates to a cement chloride ion titration outfit, it is originally the bottom at porcelain crucible's white, ammonium thiocyanate back titration excessive silver ion generated white silver thiocyanate flocculent deposit is showing the reduction to the interference of titrating in-process colour change, indicator ammonium ferric sulfate solution colour change process is comparatively obvious, has improved effectively and has titrated the terminal point and has judged the difficulty, titrate the excessive sample that causes and make useless and shortcoming such as the testing result is inaccurate, has improved the accuracy and the reliability of this method.

3. The utility model relates to a cement chloride ion titration outfit, compared with the prior art, titrate solution and can diffuse evenly fast, be unlikely to concentration and concentrate too high and lead to titrating the terminal point and judge inaccurately.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Reference numbers and corresponding part names in the drawings:

1-volumetric flask, 2-magnetic stirrer, 3-porcelain crucible, 4-digital display titrator, 401-liquid inlet pipe, 402-liquid outlet pipe, 5-optical filter, 6-bottle plug, 7-bracket.

Detailed Description

To make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the following examples and drawings, and the exemplary embodiments and descriptions thereof of the present invention are only used for explaining the present invention, and are not intended as limitations of the present invention.

Example 1:

the cement chloride ion titration apparatus shown in fig. 1 comprises a volumetric flask 1, and further comprises a digital display titrator 4, a magnetic stirrer 2 and a porcelain crucible 3 placed on the magnetic stirrer 2, wherein a liquid inlet pipe 401 of the digital display titrator 4 is inserted into the volumetric flask 1, and a liquid outlet pipe 402 of the digital display titrator 4 is positioned above the porcelain crucible 3; and further comprises a filter 5 between the porcelain crucible 3 and the viewing direction. The above-mentioned observation direction is the direction of the arrow in fig. 1.

In this example, the porcelain crucible 3 has a capacity of 250ml, and the measuring flask 1 is a brown measuring flask.

The steps of the cement chloride ion titration test carried out by using the device are as follows:

(1) 100mL of nitric acid (1+2) was prepared: 1 volume of commercially available concentrated nitric acid was mixed with 2 volumes of water and stored in a brown volumetric flask for future use;

(2) prepare 250mL of nitric acid (1+ 100): 1 volume of commercially available concentrated nitric acid was mixed with 100 volumes of water and stored in a brown volumetric flask for future use;

(3) preparing a silver nitrate standard solution: accurately weighing 8.4940g of silver nitrate powder, adding water to dissolve, transferring into a 1000mL volumetric flask, adding water to a marked line, and storing in dark place for later use;

(4) preparing an ammonium ferric sulfate indicator solution: adding 10mL of nitric acid (1+2) into 100mL of cold ammonium ferric sulfate (III) saturated aqueous solution, and shaking uniformly for later use;

(5) preparing an ammonium thiocyanate standard solution: 3.8g of ammonium bisulfate is weighed, dissolved in water, diluted to 1000 mL.

(6) Weighing about 5g (to the nearest 0.0001g) of cement sample m₀Adding 50mL of water into a beaker, stirring and dispersing, adding 50mL of nitric acid (1+2) under stirring, and heating to slightly boil for 1-2 min.

(7) 5.00mL of silver nitrate standard solution was pipetted into the above solution, a little filter pulp was added, the solution was filtered by suction through a slow filter paper previously washed with nitric acid (1+100), the filtrate was collected in a 250mL porcelain crucible or mortar, washed with nitric acid (1+100) to complete the transfer to a total solution volume of about 200mL, and left to cool to room temperature in the dark.

(8) 5mL of ferric ammonium sulfate indicator was added and titrated with standard ammonium thiocyanate solution until a reddish brown mutation was produced and the color did not disappear. Recording the volume V of the ammonium thiocyanate standard solution consumed₁If this value is less than 0.5mL, the sample mass needs to be reduced by half for retesting.

(9) Blank test was conducted in the same manner as above except that no cement sample was added to eliminateExcept the influence of system error on the detection result, the volume V of the ammonium thiocyanate standard solution consumed at the moment is recorded₂。

(10) And (4) calculating a result: the measured content (g/g,%) of chloride ions in the cement was:

example 2:

in the cement chloride ion titration apparatus shown in fig. 1, on the basis of embodiment 1, a bottle stopper 6 is disposed on a bottle mouth of the volumetric flask 1, and a through hole for a liquid inlet pipe 401 to pass through is disposed on the bottle stopper 6. The magnetic stirrer 2 is provided with a bracket 7, and the optical filter 5 is arranged on the bracket 7. And the bracket 7 is provided with a clamp 8, and the clamp 8 is used for clamping the optical filter 5.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above description is only the embodiments of the present invention, and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The cement chloride ion titration device comprises a volumetric flask (1) and is characterized by further comprising a digital display titrator (4), a magnetic stirrer (2) and a porcelain crucible (3) placed on the magnetic stirrer (2), wherein a liquid inlet pipe (401) of the digital display titrator (4) is inserted into the volumetric flask (1), and a liquid outlet pipe (402) of the digital display titrator (4) is positioned above the porcelain crucible (3); the device also comprises an optical filter (5) positioned between the porcelain crucible (3) and the observation direction.

2. The cement chloride ion titration apparatus according to claim 1, wherein a bottle stopper (6) is provided at the mouth of the volumetric flask (1), and a through hole for passing the liquid inlet pipe (401) is provided on the bottle stopper (6).

3. A cement chloride ion titration device according to claim 1, wherein a support (7) is arranged on the magnetic stirrer (2), and the optical filter (5) is arranged on the support (7).

4. A cement chloride ion titration device according to claim 3, wherein a clamp (8) is arranged on the support (7), and the clamp (8) is used for clamping the optical filter (5).