Manufacturer of Stone Powder Content Tester: Rongjida NSF-1 Stone Powder Content Tester

1、 Product Introduction:

The frequency modulation, numerical control, and technology used in the stone powder content analyzer have improved the accuracy and speed of the experiment. The stone powder content analyzer is designed according to the T0349-2005 standard of the Ministry of Transport, specifically the "Fine Aggregate Methylene Blue Test". Suitable for determining the presence of expansive clay minerals in fine aggregates and determining their content to evaluate the cleanliness of the aggregates, expressed in methylene blue value MBV.

2、 Technical parameters:

★ Mixing speed self-control: 600 ± 60r/min, 400 ± 40r/min

★ Timing device: Large 90 minute resolution of 1 second

★ Speed measurement error: ± 2r/min

★ Stirring impeller: Φ 75 ± 10mm

★ Glass bottle capacity: 1l

★ Self control function: can choose methylene blue MB measurement method or methylene blue rapid test method

★ Dimensions: 300X200X600mm

★ Weight: 15kg

3、 Usage:

★ Time setting: Turn on the power and press the "Time Setting" button first. The time display will show 3 digits. The duration of A is 999 seconds. For example, set the stirring time to 8 minutes and the dial to 480. After stirring for 8 minutes, the stirring will automatically stop. If you need to continue stirring for 4 minutes, you can set the dial to 240 and press the reset switch to restart the instrument, which will stop stirring after 4 minutes. After each mixing stop, the instrument can automatically beep and sound an alarm.

★ Speed setting: When the instrument is powered on, turn the "speed selection" switch. The speed is 600 revolutions per minute, which can be converted to 400 revolutions per minute.

★ Start the instrument: After the time and rate settings are completed, press the start switch to enter the stirring state. If the mixing is stopped halfway, press the start switch again to enter the working state.

4、 Scope of application:

This method is suitable for determining the presence of expansive clay minerals in fine aggregates and determining their content to evaluate the cleanliness of the aggregates, expressed as methylene blue value (MBV).

This method is applicable to fine aggregates smaller than 2.36mm or 0.15mm, and can also be used for quality inspection of mineral powder.

When the pass rate of 0.075mm in fine aggregate is less than 3%, this test can be considered qualified without conducting it.

5、 Formula for stone powder content analyzer:

Calculate the methylene blue value (MBV) of fine aggregate according to formula (T0349-2), up to 0.1.

In the formula: MBV - methylene blue value (g/kg), represents the grams of methylene blue consumed per kilogram of 0-2.36mm particle size samples; M - sample mass (g); V - Total amount of methylene blue solution added (mL);

★ Rapid test result evaluation of methylene blue

If there is a noticeable color halo around the sediment, the methylene blue rapid test is considered qualified. If there is no obvious color halo around the sediment, the methylene blue rapid test is considered unqualified.

The methylene blue value MBVF of the part or mineral powder less than 0.15mm is calculated according to equation (0349-3), up to 0.1.

In the formula: MBVF - methylene blue value (g/kg), represents the grams of methylene blue consumed per kilogram of 0-0.15mm particle size or mineral powder sample; M1- sample mass (g); V1- Total amount of methylene blue solution added (mL)

The calculation and evaluation of mud content or mineral powder content in fine aggregates shall be carried out according to the method of T0333.

6、 Attention:

This instrument is powered by 220V 50Hz. When the user's power supply voltage exceeds 240V or is lower than 180V, consider using a regulated power supply, otherwise it will affect the speed.

7、 Experimental steps:

★ Standard methylene blue solution (910.0g/L ± 0.1g/L standard concentration) preparation;

(1) Measure the moisture content w in methylene blue. Weigh about 5g of methylene blue powder and record the mass (mh) to 0.01g. Dry it at a temperature of 100 ℃± 5 ℃ to a constant weight (if the temperature exceeds 105 ℃, methylene blue powder will spoil), cool it in a dryer, then weigh it and record the mass (mg) to 0.01g. Calculate the moisture content w of methylene blue according to equation (T0349-1)

w = (mh-Mg)/mg×100

In the formula: MH - mass of methylene blue powder (g);

Mg - the mass of methylene blue after drying (g).

(2) Take methylene blue powder (100+w) (10g ± 0.01g)/100 (i.e. 10g of methylene blue dry powder mass) to 0.01g.

(3) Heat a beaker containing approximately 600mL of clean water, with a water temperature not exceeding 40 ℃.

(4) Add methylene blue powder while stirring, continue stirring for 45 minutes until the methylene blue powder is completely dissolved, and then cool to 20 ℃.

(5) Pour the solution into a 1L volumetric flask, rinse the beaker with clean water, and transfer all methylene blue solutions into the flask. The temperature of the flask and solution should be maintained at 20 ℃± 1 ℃, and clean water should be added to the 1L mark of the flask.

(6) Shake the volumetric flask to ensure complete dissolution of methylene blue powder. Transfer the standard solution into a dark storage bottle. The shelf life of methylene blue standard solution should not exceed 28 days. The prepared solution should be labeled with the preparation date and expiration date, and stored away from light.

★ Preparation of fine aggregate suspension

(1) Take a representative sample, reduce it to about 400g, and dry it in an oven at 105 ℃± 5 ℃ until constant weight. After cooling to room temperature, sieve out particles larger than 2.36mm and divide them into two parts for later use.

(2) Weigh 200g of the sample to 0.1g. Pour the sample into a beaker containing 500mL ± 5mL of clean water, adjust the stirrer speed to 600min, and the stirrer impeller should be about 10mm away from the bottom of the beaker. Stir for 5 min to form a suspension. Accurately add 5mL of methylene blue solution using a pipette, and then keep stirring at a speed of 400r/min ± 40r/min until the end of the experiment.

★ Determination of methylene blue adsorption capacity

(1) Place the filter paper overhead on the top of the open beaker, so that it does not come into contact with any other objects.

(2) After adding methylene blue solution and stirring at a speed of 400r/min ± 40r/min for 1 minute, the fine aggregate suspension was subjected to A color halo test on filter paper. Take a drop of suspension with a glass rod and place it on the filter paper. The droplet forms a ring on the filter paper, with the aggregate precipitate in the middle. The amount of solution should be such that the diameter of the precipitate is between 8mm and 12mm. A colorless water ring surrounds the periphery. When a light blue halo with a width of about 1mm is emitted around the edge of the sediment, the test becomes positive.

(3) If 5mL of methylene blue in batch A does not cause a color halo around the precipitate, add 5mL of methylene blue solution to the suspension, stir for 1 minute, and then use a glass rod to pick up a drop of suspension and drop it onto filter paper for a second color halo test. If no color halo still appears around the precipitate, repeat the above steps until a stable light blue A halo of about 1mm is emitted around the precipitate.

(4) Stop adding methylene blue solution dropwise, but continue stirring the suspension and conduct a color halo test every 1 minute. If the color halo disappears within 4 minutes of A, add 5 mL of methylene blue solution; If the color halo disappears within the 5th minute, add 2mL of methylene blue solution. In both cases, stirring should continue and a color halo test should be conducted until the color halo lasts for 5 minutes.

(5) Record the total volume of methylene blue solution added when the color halo lasts for 5 minutes, up to 1mL.

★ Rapid evaluation test of methylene blue

(1) Prepare samples and stir according to the requirements of Section 3.2. (1) and Section 3.2. (2).

(2) Add 30mL of methylene blue solution to a beaker at once, stir continuously at a speed of 400r/min ± 40r/min for 8 minutes, and then use a glass rod to stick a drop of suspension onto filter paper. Observe whether there is a noticeable color halo around the precipitate.

★ Determination of methylene blue value MBVF for particles smaller than 0.15mm

Accurately test the sample according to the provisions of Section 3.1-3.3 for methylene blue test, but the sample is in the range of 0-0.15mm, and 30g ± 0.1g is taken.

★ Determine the mud or stone powder content in fine aggregates using the T0333 sieving method.