Utilization method of neutralization mud

Abstract

The invention provides a utilization method of neutralization mud. The method is technically characterized by comprising the following steps: firstly, crushing and drying neutralized mud by adopting a rotary kiln, then weighing 60-70% of fly ash, 10-20% of the neutralized mud burnt by the rotary kiln and 10-20% of blast furnace slag micro powder with the specific surface area of more than or equal to 350m < 2 > / kg according to a mass ratio, adding water into the fly ash, the neutralized mud and the blast furnace slag micro powder, uniformly mixing, carrying out disc pelletizing, and drying the made balls for 1-2 days. The dried balls are conveyed into a high-temperature rotary kiln through a belt to be roasted, the rotating speed of the rotary kiln is 40-50 s / r, the temperature of the kiln head is 1100-1130 DEG C, and the temperature of the kiln tail is 300-600 DEG C. And roasting to form the ceramsite.

Description

Technical Field

[0001] The present invention relates to the field of comprehensive resource utilization, and in particular to a method for utilizing neutralized mud. Background Art

[0002] Neutralizing sludge is the product of neutralization, flocculation, precipitation, concentration, and filtration of waste acid water from stainless steel pickling in steel mills. It contains approximately 55% water and currently has no repurposing options. To achieve a circular economy and improve resource utilization, research on how to utilize neutralizing sludge is urgent.

[0003] The purpose of the present invention is to develop a utilization process of neutralization mud and realize the recycling utilization of neutralization mud. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for utilizing neutralized mud in order to solve the above problems.

[0005] The object of the present invention is achieved as follows: A method for utilizing neutralization mud, comprising the following steps: Step 1: first, the neutralization mud is transported to the tail of a low-temperature rotary kiln via a belt, and a screw conveyor is installed at the tail of the rotary kiln, and the neutralization mud is transported to the rotary kiln via the screw conveyor; Step 2: The rotation speed of the rotary kiln is 50-70 seconds / revolution, the temperature of the kiln head is 300-400°C, and the temperature of the kiln tail is 100-200°C, and the moisture content of the neutralization mud is reduced to less than 2%, and the particle size is less than 1mm; Step 3: 60%-70% of fly ash, 10%-20% of the neutralization mud after burning in the rotary kiln, and 10-20% of blast furnace slag powder are weighed according to the mass ratio, and the specific surface area of ​​the blast furnace slag powder is 350-410m 2 / kg, fly ash, neutralization mud, and blast furnace slag powder are mixed with water and then pelletized on discs. The pellets are then dried for 24-48 hours. Step 4: The dried pellets are transported by belt conveyor into a high-temperature rotary kiln for roasting. The rotary kiln rotates at a speed of 40-50 seconds per revolution, with a temperature of 1100-1130°C at the kiln head and 300-600°C at the kiln tail. After roasting, ceramsite is formed. Step 5: Samples are taken to test the compressive strength of the ceramsite.

[0006] Step 5: Sampling test of the compressive strength of expanded clay is to test 20-30 expanded clay particles, and the compressive strength of each expanded clay particle is ≥500N.

[0007] The beneficial effects of the present invention include developing a process for utilizing neutralization mud, which enables internal recycling of neutralization mud. The implementation of the present invention not only meets national environmental protection requirements but also resolves bottlenecks that hinder the sustainable development of my country's stainless steel industry, resulting in significant economic and social benefits. DETAILED DESCRIPTION

[0008] A method for utilizing neutralization mud comprises the following steps: firstly crushing and drying the neutralization mud in a rotary kiln, and then weighing 60%-70% fly ash, 10%-20% neutralization mud after burning in a rotary kiln, and 10-20% blast furnace slag powder according to mass proportion, wherein the specific surface area of ​​the blast furnace slag powder is ≥350m 2 / kg, fly ash, neutralization mud, and blast furnace slag powder are mixed with water and then pelletized on discs. The pellets are dried for 1-2 days. The dried pellets are transported by belt conveyor to a high-temperature rotary kiln for roasting. The rotary kiln rotates at a speed of 40-50 seconds per revolution, with a kiln head temperature of 1100-1130°C and a kiln tail temperature of 300-600°C. After roasting, ceramsite is formed.

[0009] The present invention provides a method for utilizing neutralization mud. First, the neutralization mud is dried and crushed in a rotary kiln. A certain proportion of fly ash and blast furnace slag powder is then added to form disc pellets. The pellets are dried and then calcined in a rotary kiln to form ceramsite. The method for utilizing the neutralization mud comprises the following steps: 1. The neutralization mud is first transported via a belt to the tail of a low-temperature rotary kiln. A screw conveyor is installed at the tail of the rotary kiln to transport the neutralization mud into the rotary kiln.

[0010] 2. The rotation speed of the rotary kiln is 50-70 seconds / revolution, the temperature at the kiln head is 300-400℃, and the temperature at the kiln tail is 100-200℃. The moisture content of the neutralized mud is reduced to below 2%, and the particle size is less than 1mm.

[0011] 3. Then weigh 60%-70% fly ash, 10%-20% neutralized mud after rotary kiln burning, and 10-20% blast furnace slag powder according to the mass ratio. The specific surface area of ​​blast furnace slag powder is ≥350m 2 / kg, mix fly ash, neutralization mud and blast furnace slag powder with water and make disc balls. Dry the balls for 1-2 days.

[0012] 4. The dried balls are then transported by belts into a high-temperature rotary kiln for roasting. The rotary kiln rotates at a speed of 40-50 seconds per revolution, with a kiln head temperature of 1100-1130°C and a kiln tail temperature of 300-600°C. After roasting, ceramsite is formed.

[0013] 5. Sampling test of expanded clay compressive strength, test 20 expanded clays, the average compressive strength is ≥500N.

[0014] The specific implementation manner of the present invention will be described in detail below with reference to the examples, but the specific implementation manner is not limited to the following examples. Example 1

[0015] 1. First, the neutralized mud is transported to the tail of the low-temperature rotary kiln via a belt. A screw conveyor is installed at the tail of the rotary kiln, which transports the acid mud to the rotary kiln via the screw conveyor (the addition of acid mud to the rotary kiln is a continuous operation. As long as the rotary kiln equipment is normal, production can continue).

[0016] 2. The rotation speed of the rotary kiln is 60 seconds / revolution, the temperature of the kiln head is 350℃, the temperature of the kiln tail is 160℃, the moisture content of the dried neutralized mud is 1.4%, and the particle size is less than 1mm.

[0017] 3. Then weigh 3600kg of fly ash, 1200kg of neutralized mud after burning in rotary kiln, and 1200kg of blast furnace slag powder according to the mass ratio. The specific surface area of ​​blast furnace slag powder is 390m 2 / kg, fly ash, neutralization mud and blast furnace slag powder are mixed with water and disc balling is carried out. The balls are dried for 2 days.

[0018] 4. The dried balls are then transported by belts into a high-temperature rotary kiln for roasting. The rotary kiln rotates at a speed of 40 seconds per revolution, with a kiln head temperature of 1100°C and a kiln tail temperature of 500°C. After roasting, ceramsite is formed.

[0019] 5. Sampling test of expanded clay compressive strength, 20 expanded clays were tested, and the average compressive strength was 610N. Example 2

[0020] 1. First, the neutralized mud is transported to the tail of the low-temperature rotary kiln via a belt. A screw conveyor is installed at the tail of the rotary kiln, which transports the acid mud to the rotary kiln via the screw conveyor (the addition of acid mud to the rotary kiln is a continuous operation. As long as the rotary kiln equipment is normal, production can continue).

[0021] 2. The rotation speed of the rotary kiln is 70 seconds / revolution, the temperature at the kiln head is 300℃, the temperature at the kiln tail is 120℃, the moisture content of the dried neutralized mud is 1.2%, and the particle size is less than 1mm.

[0022] 3. Then weigh 4900kg of fly ash, 1050kg of neutralized mud after burning in rotary kiln, and 1300kg of blast furnace slag powder according to the mass ratio. The specific surface area of ​​blast furnace slag powder is 410m 2 / kg, fly ash, neutralization mud and blast furnace slag powder are mixed with water and disc balling is carried out. The balls are dried for 2 days.

[0023] 4. The dried balls are then transported by belts into a high-temperature rotary kiln for roasting. The rotary kiln rotates at a speed of 46 seconds per revolution, with a kiln head temperature of 1120°C and a kiln tail temperature of 480°C. After roasting, ceramsite is formed.

[0024] 5. Sampling test of expanded clay compressive strength, 20 expanded clays were tested, and the average compressive strength was 570N. Example 3

[0025] 1. First, the neutralized mud is transported to the tail of the low-temperature rotary kiln via a belt. A screw conveyor is installed at the tail of the rotary kiln, which transports the acid mud to the rotary kiln via the screw conveyor (the addition of acid mud to the rotary kiln is a continuous operation. As long as the rotary kiln equipment is normal, production can continue).

[0026] 2. The rotation speed of the rotary kiln is 66 seconds / revolution, the temperature of the kiln head is 340℃, the temperature of the kiln tail is 130℃, the moisture content of the dried neutralized mud is 1.0%, and the particle size is less than 1mm.

[0027] 3. Then weigh 3000kg of fly ash, 800kg of neutralized mud after burning in rotary kiln, and 900kg of blast furnace slag powder according to the mass ratio. The specific surface area of ​​blast furnace slag powder is 370m 2 / kg, fly ash, neutralization mud and blast furnace slag powder are mixed with water and disc balling is carried out. The balls are dried for 2 days.

[0028] 4. The dried balls are then transported by belts into a high-temperature rotary kiln for roasting. The rotary kiln rotates at a speed of 46 seconds per revolution, with a kiln head temperature of 1120°C and a kiln tail temperature of 480°C. After roasting, ceramsite is formed.

[0029] 5. Sampling test of expanded clay compressive strength, 20 expanded clays were tested, and the average compressive strength was 780N.

[0030] The above description is only a specific embodiment of the present invention, but the structural features protected by the present invention are not limited thereto. Any changes or modifications made by any technician in this field within the scope of the present invention are included in the patent scope of the present invention.

Claims

1. A method for utilizing neutralized mud, characterized by: The following steps are involved: Step 1: First, the neutralization mud is transported to the tail of the low-temperature rotary kiln via a belt. A screw conveyor is installed at the tail of the rotary kiln, and the neutralization mud is transported to the rotary kiln via the screw conveyor; Step 2: The rotary kiln rotates at a speed of 50-70 seconds / revolution, the kiln head temperature is 300-400°C, and the kiln tail temperature is 100-200°C. The moisture content of the neutralized mud is reduced to below 2%, and the particle size is less than 1mm. Step 3: Weigh 60%-70% fly ash, 10%-20% neutralized mud after rotary kiln burning, and 10-20% blast furnace slag powder according to mass ratio. The specific surface area of ​​blast furnace slag powder is 350-410m 2 / kg, fly ash, neutralization mud and blast furnace slag powder are mixed with water and then disc ball is made. The made balls are dried for 24-48 hours; Step 4: The dried balls are transported by belts into a high-temperature rotary kiln for roasting. The speed of the rotary kiln is 40-50 seconds / rotation, the temperature at the kiln head is 1100-1130℃, and the temperature at the kiln tail is 300-600℃. After roasting, ceramsite is formed. Step 5: Sampling and testing the compressive strength of expanded clay.

2. The method for utilizing neutralized mud according to claim 1, wherein: Step 5: Sampling test of the compressive strength of expanded clay is to test 20-30 expanded clay particles, and the compressive strength of each expanded clay particle is ≥500N.