A method for processing waste spinning substitute fuel and detecting chloride ions in cement production

Abstract

The application provides a waste spinning substitute fuel treatment and chloride ion detection method for cement production, and belongs to the technical field of substitute fuel.The waste spinning is crushed, mixed with zinc oxide and alkali in water at 35-50 DEG C, filtered, dried, and waste spinning substitute fuel for cement production is obtained.The waste spinning is treated in a reasonable way, the heat value is kept unchanged, the chloride ion content is greatly reduced, and the control of chloride ion in the substitute fuel is realized;when the treated waste spinning substitute fuel is used for cement production, the clinker chloride ion content can be kept within a controllable range.In addition, the chloride ion detection method provided by the application detects the chloride ion content by using existing detection equipment and conventional chemicals, without the need to additionally purchase equipment, reduces the use of dangerous chemicals such as potassium thiocyanate and ferric ammonium sulfate, and is simple to operate, cost-saving and space-saving.

Description

Technical Field

[0001] This invention relates to the field of alternative fuel technology, specifically to a method for treating waste textiles used in cement production as alternative fuel and for detecting chloride ions. Background Technology

[0002] With the improvement of people's living standards and the change of consumption concepts, the pace of textile upgrading has accelerated, and the amount of waste textiles generated is increasing day by day.

[0003] Compared to pulverized coal, waste textiles have higher volatile matter, lower ash content, lower moisture content, and a considerable calorific value, making them a promising alternative fuel. Recycling waste textiles as an alternative fuel can not only reduce their environmental burden and achieve effective resource reuse and waste reduction, but also alleviate the domestic coal shortage to some extent. However, the combustion of waste textiles produces harmful substances such as chloride (Cl) and sulfur (S). In particular, the national standard for cement has a chloride ion limit of 0.06%, while the chloride content in waste textiles ranges from 0.2% to 0.6%. Without control, the large-scale use of waste textiles as alternative fuel will lead to excessive chloride ions in clinker, and there is also a risk of ring formation in the kiln. Therefore, this invention aims to provide a treatment method for waste textiles that reduces the generation and emission of toxic substances such as chloride (Cl) and sulfur when used as an alternative fuel. Summary of the Invention

[0004] To address the shortcomings of the existing technologies, this invention provides a method for treating waste textiles used in cement production as alternative fuel and for detecting chloride ions. By pretreating the waste textiles in a reasonable manner, the chloride ion content can be effectively reduced.

[0005] To achieve the above objectives, the specific technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a method for treating waste textiles used as alternative fuel in cement production, wherein the waste textiles are crushed and mixed with zinc oxide and alkali in water at 35-50 °C, filtered, and dried to obtain waste textiles used as alternative fuel in cement production.

[0007] In the existing technology, burning waste textiles directly as alternative fuel will cause excessive chloride ions in the clinker. This invention adopts a reasonable method to pretreat waste textiles, which can significantly reduce the chloride ion content in waste textiles while maintaining their calorific value. This will increase their usage in cement production, reduce production costs, achieve effective reuse of resources, and reduce resource waste.

[0008] Furthermore, the mass ratio of the waste textile, zinc oxide, and alkali is 1000:(1~5):(10~30).

[0009] Furthermore, the mass-to-volume ratio of the waste textile to water (g / mL) is 1:(3~10).

[0010] Furthermore, the alkali is potassium hydroxide or sodium hydroxide.

[0011] Furthermore, the mixing time is 2 to 5 hours.

[0012] Furthermore, the size of the shredded waste textile is less than 20 mm.

[0013] Furthermore, the waste textiles include at least one of old clothing, bedding, curtains, and carpets.

[0014] Secondly, the present invention provides waste textile alternative fuel obtained by the method described above.

[0015] Thirdly, the present invention provides the application of the waste textile alternative fuel in cement production.

[0016] Fourthly, the present invention provides a method for detecting chloride ions in the waste textile alternative fuel, comprising the following steps:

[0017] (1) Weigh the waste textile alternative fuel sample and mix it evenly with Eschka mixture in a crucible to obtain a mixture. Then cover the mixture with a certain mass of Eschka mixture and perform calcination treatment.

[0018] (2) Transfer the calcined product into a beaker and rinse the inner wall of the crucible with hot water, then pour the rinsing liquid into the beaker;

[0019] (3) Filter the mixed solution obtained in step (2), rinse the residue with hot water 1-2 times, then transfer the residue into a funnel, and then carefully rinse the filter paper and residue with hot water until there is no turbidity when tested with silver nitrate solution;

[0020] (4) Take the liquid from step (3), place it in a beaker, and use an automatic potentiometric titration method to detect the chloride ion content.

[0021] Furthermore, in the mixture, the mass ratio of the waste textile alternative fuel sample to the Eschka mixture is 1:4.

[0022] Furthermore, the burning temperature is 660~700 ℃, and the time is 2~4 h.

[0023] The method for detecting chloride ions in the waste textile alternative fuel is as follows:

[0024] (1) Weigh 1 g of waste textile alternative fuel sample and 4 g of Eschka mixture and mix them evenly in a crucible to obtain a mixture. Then cover the mixture with 3 g of Eschka mixture and calcine at 660~700 ℃ for 2~4 h.

[0025] (2) Transfer the calcined product into a 250 mL beaker, rinse the inner wall of the crucible with 50-60 mL of hot water, and pour the rinsing solution into the beaker;

[0026] (3) Filter the solution using the decantation method with qualitative filter paper, rinse the residue with hot water 1-2 times, then transfer the residue into a funnel, and rinse the filter paper and residue carefully with hot water until there is no turbidity when tested with silver nitrate solution; control the volume of the filtrate to 110 mL during the filtration and rinsing process, cool it and make up to 250 mL, and mix well.

[0027] (4) Take the liquid (less than 50 mL) from step (3) and place it in a 250 mL dry beaker. Use an automatic potentiometric titration method to detect the chloride ion content.

[0028] Compared with the prior art, the advantages of the present invention are:

[0029] (1) The present invention uses a reasonable method to treat waste textiles, thereby controlling the chloride ions of alternative fuels and ensuring that the chloride ion content of clinker is within a controllable range when it is used in cement production; at the same time, it can also increase the amount of waste textile alternative fuels used in cement production and reduce production costs.

[0030] (2) The chloride ion detection method provided by the present invention uses existing detection equipment and conventional reagents to detect chloride ion content without the need to purchase additional equipment, which reduces the use of hazardous chemicals such as potassium thiocyanate and ferric ammonium sulfate. It is also simple to operate and saves costs and space. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This invention provides a method for treating waste textiles used as alternative fuel in cement production. The waste textiles are crushed and mixed with zinc oxide and alkali in water at 35-50°C, filtered, and dried to obtain waste textiles as alternative fuel for cement production.

[0033] In some examples, the mass ratio of the waste textile, zinc oxide, and alkali is 1000:(1~5):(10~30).

[0034] In some examples, the mass-to-volume ratio of the waste textile to water (g / mL) is 1:(3~10); in the following specific embodiments, the mass-to-volume ratio of the waste textile to water (g / mL) is 1:5.

[0035] In some examples, the base is potassium hydroxide or sodium hydroxide.

[0036] In some examples, the mixing time is 2 to 5 hours.

[0037] In some examples, the size of the shredded waste textiles is less than 20 mm.

[0038] In some examples, the waste textiles include at least one of old clothing, bedding, curtains, and carpets.

[0039] The method for detecting chloride ions in the waste textile alternative fuel is as follows:

[0040] (1) Weigh 1 g of waste textile alternative fuel sample and 4 g of Eschka mixture and mix them evenly in a crucible to obtain a mixture. Then cover the mixture with 3 g of Eschka mixture and calcine at 660~700 ℃ for 2~4 h.

[0041] (2) Transfer the calcined product into a 250 mL beaker, rinse the inner wall of the crucible with 50-60 mL of hot water, and pour the rinsing solution into the beaker;

[0042] (3) Filter the solution using the decantation method with qualitative filter paper, rinse the residue with hot water 1-2 times, then transfer the residue into a funnel, and rinse the filter paper and residue carefully with hot water until there is no turbidity when tested with silver nitrate solution; control the volume of the filtrate to 110 mL during the filtration and rinsing process, cool it and make up to 250 mL, and mix well.

[0043] (4) Take less than 50 mL of the liquid from step (3) and place it in a 250 mL dry beaker. Use an automatic potentiometric titration method to detect the chloride ion content.

[0044] Example 1

[0045] An alternative fuel for cement production using waste textiles (waste carpets)

[0046] Waste textiles are crushed into pieces smaller than 20 mm and then mixed with zinc oxide and sodium hydroxide in water at 40 °C for 3 h. After filtration and drying, waste textiles are obtained as a substitute fuel for cement production. The mass ratio of the waste textiles, zinc oxide, and sodium hydroxide is 1000:5:10.

[0047] Chloride ion content in waste textiles before and after treatment:

[0048] (1) Weigh 1 g of waste textile samples before and after treatment and 4 g of Eschka mixture and mix them evenly in a crucible to obtain a mixture. Then cover the mixture with 3 g of Eschka mixture and calcine at 680 °C for 3 h.

[0049] (2) Transfer the calcined product into a 250 mL beaker, rinse the inner wall of the crucible with 50 mL of hot water, and pour the rinsing solution into the beaker;

[0050] (3) Filter the solution using the decantation method with qualitative filter paper, rinse the residue twice with hot water, then transfer the residue into a funnel, and rinse the filter paper and residue carefully with hot water until there is no turbidity when tested with silver nitrate solution; control the volume of the filtrate to 110 mL during the filtration and rinsing process, cool it and make up to 250 mL, and mix well.

[0051] (4) Take 50 mL of the liquid from step (3) and place it in a 250 mL dry beaker. Use automatic potentiometric titration to detect the chloride ion content. The results are shown in Table 1.

[0052] Example 2

[0053] A substitute fuel for waste textiles (old clothes and curtains) used in cement production

[0054] Waste textiles are crushed into pieces smaller than 20 mm and then mixed with zinc oxide and sodium hydroxide in water at 40 °C for 3 h. After filtration and drying, waste textiles are obtained as a substitute fuel for cement production. The mass ratio of the waste textiles, zinc oxide, and sodium hydroxide is 1000:1:30.

[0055] Chloride ion content in waste textiles before and after treatment:

[0056] (1) Weigh 1 g of waste textile samples before and after treatment and 4 g of Eschka mixture and mix them evenly in a crucible to obtain a mixture. Then cover the mixture with 3 g of Eschka mixture and calcine at 680 °C for 3 h.

[0057] (2) Transfer the calcined product into a 250 mL beaker, rinse the inner wall of the crucible with 50 mL of hot water, and pour the rinsing solution into the beaker;

[0058] (3) Filter the solution using the decantation method with qualitative filter paper, rinse the residue twice with hot water, then transfer the residue into a funnel, and rinse the filter paper and residue carefully with hot water until there is no turbidity when tested with silver nitrate solution; control the volume of the filtrate to 110 mL during the filtration and rinsing process, cool it and make up to 250 mL, and mix well.

[0059] (4) Take 50 mL of the liquid from step (3) and place it in a 250 mL dry beaker. Use automatic potentiometric titration to detect the chloride ion content. The results are shown in Table 1.

[0060] Comparative Example 1

[0061] An alternative fuel for cement production using waste textiles (waste carpets)

[0062] Waste textiles are crushed into pieces smaller than 20 mm and mixed with sodium hydroxide in water at 40 °C for 3 h. The mixture is then filtered and dried to obtain waste textile alternative fuel for cement production. The mass ratio of the waste textiles to sodium hydroxide is 1000:15.

[0063] The chloride ion content in the treated waste textiles was detected using the method described in Example 1, and the results are shown in Table 1.

[0064] Comparative Example 2

[0065] An alternative fuel for cement production using waste textiles (waste carpets)

[0066] Waste textiles are crushed into pieces smaller than 20 mm and then mixed with zinc oxide and sodium hydroxide in water at 40 °C for 3 h. After filtration and drying, waste textiles are used as a substitute fuel for cement production. The mass ratio of the waste textiles, zinc oxide and sodium hydroxide is 1000:0.5:14.5.

[0067] The chloride ion content in the treated waste textiles was detected using the method described in Example 1, and the results are shown in Table 1.

[0068] Comparative Example 3

[0069] An alternative fuel for cement production using waste textiles (waste carpets)

[0070] Waste textiles are crushed into pieces smaller than 20 mm and then mixed with zinc oxide and sodium hydroxide in water at 40 °C for 3 h. After filtration and drying, waste textiles are used as a substitute fuel for cement production. The mass ratio of the waste textiles, zinc oxide, and sodium hydroxide is 1000:6:9.

[0071] The chloride ion content in the treated waste textiles was detected using the method described in Example 1, and the results are shown in Table 1.

[0072] Table 1: Calorific value and chloride ion content of waste textiles before and after treatment

[0073]

[0074] As shown in Table 1, the present invention employs a reasonable method to treat waste textiles, which can significantly reduce their chloride ion content while maintaining their calorific value. Using the treated waste textiles as alternative fuel in cement production ensures that the chloride ion content of the clinker remains within a controllable range. Simultaneously, it can increase the usage of waste textile alternative fuel in cement production, thereby reducing costs. However, during the waste textile treatment process, if alkali is used to completely replace zinc oxide (Comparative Example 1), or alkali is used to partially replace zinc oxide (Comparative Example 2), or zinc oxide is used to partially replace alkali (Comparative Example 3), the chloride ion content in the resulting waste textile alternative fuel is still relatively high.

[0075] The above detailed embodiments describe the implementation of the present invention; however, the present invention is not limited to the specific details described in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A method for treating waste textiles used as alternative fuel in cement production, characterized in that, Waste textiles are crushed and mixed with zinc oxide and alkali in water at 35-50°C, filtered, and dried to obtain waste textile alternative fuel for cement production; the alkali is potassium hydroxide or sodium hydroxide; the mass ratio of waste textiles, zinc oxide, and alkali is 1000:(1-5):(10-30).

2. The method for treating waste textiles used as alternative fuel in cement production according to claim 1, characterized in that, The mixing time is 2-5 hours.

3. The method for treating waste textiles used as alternative fuel in cement production according to claim 1, characterized in that, The size of the shredded waste textile is less than 20 mm.

4. Waste textile alternative fuel obtained by the method described in any one of claims 1 to 3.

5. The application of waste textile alternative fuel as described in claim 4 in cement production.

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