Production process of polyferric sulfate

Abstract

The invention relates to a production process of polyferric sulfate. The production process comprises the following steps: a raw material treatment step: crushing and screening raw materials; an oxidation reaction step: adding an oxidizing agent into the treated raw materials for stirring reaction; and a polymerization reaction step: adding a polymerizing agent into the oxidized raw material for stirring reaction, removing impurities from the polymerized raw material, and drying to obtain a solid product. The problem that an oxidizing agent and a polymerizing agent react incompletely in an existing scheme is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the chemical industry, especially to a production process of polymeric ferric sulfate. BACKGROUND

[0002] Polymeric ferric sulfate is a kind of efficient inorganic polymer flocculant, which is widely used in water treatment, wastewater treatment and other fields. In the preparation of polymeric ferric sulfate, ferrous sulfate and industrial waste sulfuric acid are used as raw materials, and oxidation reaction and polymerization reaction are carried out in turn.

[0003] In the oxidation reaction, the oxidizing agent is added and stirred, and in the polymerization reaction, the polymerization agent is added and stirred. In the preparation process, the reaction kettle is used for stirring, so that the oxidation agent and the polymerization agent do not react completely.

[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0005] In view of the above shortcomings of the prior art, the purpose of the present application is to provide a production process of polymeric ferric sulfate to solve the problem of incomplete reaction of oxidizing agent and polymerization agent in the prior art.

[0006] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows: A production process of polymeric ferric sulfate; The production process comprises the following steps: raw material treatment step: the raw material is treated by crushing and screening; oxidation reaction step: the treated raw material is added with an oxidizing agent for stirring reaction; polymerization reaction step: the oxidized raw material is added with a polymerization agent for stirring reaction, and the polymerized raw material is dried after removing impurities to obtain a solid product.

[0007] Further, in the raw material treatment step, the raw material comprises ferrous sulfate and sulfuric acid; in the oxidation reaction step, the oxidizing agent comprises sodium chlorate, hydrogen peroxide and oxygen; and in the polymerization reaction step, the polymerization agent comprises sodium hydroxide.

[0008] Further, the production process further comprises a testing step after the polymerization reaction step: detecting the iron content, salt base and pH value of the solid product; and placing the solid product in a dry and ventilated environment after detection.

[0009] Further, in the raw material treatment step, the ferrous sulfate is ground and crushed and then enters the screening space; a gas is injected into the screening space, the gas blows up the light crushed ferrous sulfate and recovers it; and the sulfuric acid is screened and recovered.

[0010] The further technical scheme is that in the oxidation reaction step, the ferrous sulfate and sulfuric acid are mixed by stirring, the mixing temperature is 30-35 DEG C, the mixing time is 30-35 min, and the stirring speed is 90 r / min; the oxidant is added and the stirring reaction is continuously carried out; the stirring speed is increased by 40-55%, the reaction temperature is 110-115 DEG C, and the reaction time is 55-60 min.

[0011] The further technical scheme is that in the polymerization reaction step, the oxidized raw material is added with the polymerization agent, and the fast and slow stirring reactions are alternately carried out.

[0012] The further technical scheme is that in the polymerization reaction step, the stirring speed is 105-110 r / min, the reaction time is 25-30 min, and the reaction temperature is 80-85 DEG C.

[0013] Compared with the prior art, the beneficial technical effects of the present application are as follows: (1) the injection amount and the flow rate of the gas are controlled, and the preset mass of the crushed ferrous sulfate is blown up, so as to screen the crushed ferrous sulfate.

[0014] (2) the ferrous sulfate and the sulfuric acid are pre-mixed, and can be quickly maintained at the temperature and the stirring speed required by the oxidation reaction, so that the treated raw material and the oxidant can be fully contacted and reacted in a short time; most of the oxidant is added at 30-35 DEG C during the adding process of the oxidant, and all the oxidant needs to be added before the reaction temperature reaches, and the oxidant consumption and decomposition are less; the adding process is carried out in multiple times, so that the treated raw material and the oxidant are fully contacted and reacted.

[0015] (3) the oxidized raw material and the polymerization agent are alternately subjected to the fast stirring and the slow stirring, so that the oxidized raw material and the polymerization agent are fully stirred and reacted; because the flow speed of the oxidized raw material and the polymerization agent is slow in the slow stirring area, the oxidized raw material and the polymerization agent have sufficient reaction time; because the flow speed of the oxidized raw material and the polymerization agent is fast in the fast stirring area, the oxidized raw material and the polymerization agent can be fully stirred; the oxidized raw material and the polymerization agent are alternately and superimposedly subjected to the full stirring and the full reaction, so that the reaction effect is better. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A flow chart of the production process of the embodiment of the present application is shown.

[0017] Figure 2 A structure schematic diagram in the raw material treatment step of the embodiment of the present application is shown.

[0018] Figure 3 A structure schematic diagram in the polymerization reaction step of the embodiment of the present application is shown.

[0019] Figure 4 A structure schematic diagram in the polymerization reaction step of the embodiment of the present application is shown. Figure 3Schematic diagram of the distribution of medium-fast stirring area and slow stirring area.

[0020] Markings in the accompanying drawings: 1, screening space; 11, first grinding disc; 111, through hole; 112, pipeline; 12, second grinding disc; 2, stirring space; 21, stirring shaft; 22, stirring blade; 23, fast stirring area; 24, slow stirring area. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention clearer, the device proposed in the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the efficacy and purpose that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0022] Figure 1 A flow chart of the production process of an embodiment of the present invention is shown. Figure 2 The schematic diagram of the structure of the raw material processing step in the embodiment of the present invention is shown. Figures 1-2 As shown, the present invention discloses a production process of polyferric sulfate.

[0023] The production process of polyferric sulfate includes the following steps: Raw material processing steps: the raw materials are crushed and screened.

[0024] The raw materials in the raw material processing step include ferrous sulfate and sulfuric acid.

[0025] Raw material processing steps: grind the ferrous sulfate into powder and then enter the screening space 1.

[0026] The lower end of the screening space 1 is fixedly provided with a first grinding disc 11 horizontally, and a through hole 111 is formed in the middle position of the first grinding disc 11. The lower end of the screening space 1 is rotatably provided with a second grinding disc 12 horizontally, and the first grinding disc 11 and the second grinding disc 12 are oppositely arranged. The through hole 111 is connected with the lower end of a pipeline 112, and the upper end of the pipeline 112 is used for injecting ferrous sulfate. The ferrous sulfate enters between the first grinding disc 11 and the second grinding disc 12, the second grinding disc 12 is driven to rotate by a motor, and the working surfaces of the first grinding disc 11 and the second grinding disc 12 act on the ferrous sulfate to grind and crush the ferrous sulfate. Under the action of inertia, the crushed ferrous sulfate gradually moves to the outer periphery of the first grinding disc 11 and the second grinding disc 12 and finally enters the lower end of the screening space 1.

[0027] The lower end of the screening space 1 is injected with gas, and the gas blows up the light crushed ferrous sulfate for recycling.

[0028] By controlling the injection amount and flow rate of the gas, the light crushed ferrous sulfate of a preset mass is blown up, so as to screen the crushed ferrous sulfate.

[0029] The ferrous sulfate is screened and recycled.

[0030] The sulfuric acid is waste sulfuric acid containing impurities. The impurities are filtered after screening. The sulfuric acid of a preset concentration is obtained by diluting the sulfuric acid or adding sulfuric acid with high concentration.

[0031] Oxidation reaction step: the treated raw material is added with an oxidizing agent for stirring reaction.

[0032] The oxidizing agent in the oxidation reaction step includes sodium chlorate, hydrogen peroxide and oxygen.

[0033] Oxidation reaction step: ferrous sulfate and sulfuric acid are mixed by stirring. The mixing temperature is 30-35℃, the mixing time is 30-35min, and the stirring speed is 90r / min. The ferrous sulfate and the sulfuric acid are mixed by short-time low-speed stirring, so as to complete the pre-mixing of the ferrous sulfate and the sulfuric acid, facilitate the reaction temperature and the stirring speed to be quickly reached after the oxidizing agent is added subsequently, and realize the rapid oxidation reaction.

[0034] The stirring reaction is continued after the oxidizing agent is added, and the oxidizing agent is added three times before the reaction temperature is reached. The stirring speed is increased by 40-55%, the reaction temperature is 110-115℃, and the reaction time is 55-60min.

[0035] The oxidizing agent adding process includes: the first time, 70% of the mass of the oxidizing agent is added, the second time, 20% of the mass of the oxidizing agent is added, and the third time, 10% of the mass of the oxidizing agent is added.

[0036] If the adding speed of the oxidizing agent is slow, it is beneficial for the full contact between the treated raw material and the oxidizing agent, but it will increase the reaction time. If the adding time is delayed, the treated raw material will produce a precipitate. In the present application, the ferrous sulfate and sulfuric acid are pre-mixed, which can quickly maintain the required temperature and stirring speed of the oxidation reaction, so that the treated raw material and the oxidizing agent can fully contact and react in a short time.

[0037] A large amount of heat is released in the oxidation reaction step, which will consume part of the oxidizing agent and decompose. In order to avoid the above situation, most of the oxidizing agent is added at 30-35℃ during the adding process of the oxidizing agent, and all the oxidizing agent needs to be added before the reaction temperature reaches, and the oxidizing agent decomposition is less. The adding process is divided into several times, so that the treated raw material and the oxidizing agent can fully contact and react.

[0038] Figure 3 The structural schematic diagram in the polymerization reaction step of the embodiment of the present application is shown. Figure 4 The structural schematic diagram in the polymerization reaction step of the embodiment of the present application is shown. Figure 3 The distribution diagram of the fast stirring area and the slow stirring area in the present application is shown. The polymerization reaction step is shown in the present application. Figures 1-4 The polymerization reaction step is shown in the present application, that is, the treated raw material is added to the polymerization agent for stirring reaction, and the treated raw material is dried after removing impurities to obtain a solid product.

[0039] The polymerization agent in the polymerization reaction step includes sodium hydroxide.

[0040] The treated raw material is stirred in the polymerization reaction step, and the polymerization agent is slowly added during the stirring process.

[0041] The treated raw material is added to the stirring space 2, the eccentric stirring shaft 21 is installed in the stirring space 2, and the stirring blade 22 is formed on the stirring shaft 21. The stirring shaft 21 is driven by a motor, the stirring shaft 21 rotates to drive the stirring blade 22 to move, and the stirring blade 22 stirs and reacts with the treated raw material and the polymerization agent.

[0042] Due to the eccentric installation of the stirring shaft 21, a fast stirring area 23 and a slow stirring area 24 are formed in the stirring space 2. The stirring shaft 21 and the stirring blade 22 are located in the fast stirring area 23, and the slow stirring area 24 is located on one side of the edge of the fast stirring area 23. For example, the fast stirring area 23 is circular, and the slow stirring area 24 is circular arc. The rotation of the stirring shaft 21 drives the stirring blade 22 to move at high speed in the fast stirring area 23, so that the flow rate of the oxidized raw material and the polymerization agent in the fast stirring area 23 is fast. Under the action of inertia, the oxidized raw material and the polymerization agent will transition from the fast stirring area 23 to the slow stirring area 24. Due to the fast moving speed of the stirring blade 22, the oxidized raw material and the polymerization agent in the slow stirring area 24 will transition to the fast stirring area 23, and the cycle is repeated, so that the oxidized raw material and the polymerization agent realize alternating fast stirring and slow stirring, so that the oxidized raw material and the polymerization agent are fully stirred. Because the flow rate of the oxidized raw material and the polymerization agent in the slow stirring area 24 is slow, the oxidized raw material and the polymerization agent have sufficient reaction time. Because the flow rate of the oxidized raw material and the polymerization agent in the fast stirring area 23 is fast, the oxidized raw material and the polymerization agent can be fully stirred. The oxidized raw material and the polymerization agent are alternately and superimposed by full stirring and full reaction, so that the reaction effect is good.

[0043] The stirring speed in the polymerization reaction step is 105-110 r / min, the reaction time is 25-30 min, and the reaction temperature is 80-85°C. By alternating slow and fast stirring, the stirring is sufficient, and the stirring speed and reaction time are reduced.

[0044] The polymerization reaction step further includes a testing step: detecting the iron content, the salt base, and the ph value of the solid product.

[0045] Specifically, the iron content of the solid product is ≥19%, the salt base of the solid product is 8-16%, and the ph value of the solid product is 2-3. Further, the detection indexes of the solid product further include the content of reducing substances, the content of heavy metals and harmful elements, the content of insoluble substances, and the density.

[0046] After detection, the solid product is placed in a dry and ventilated environment. The solid product avoids light decomposition and avoids absorbing moisture, which affects the performance.

[0047] The following two examples illustrate the present application: First embodiment: The production process of the polymerized ferric sulfate includes the following steps: The raw material treatment step: the raw material is crushed and sieved.

[0048] In the raw material treatment step, the raw material includes ferrous sulfate and sulfuric acid. The first grinding disc 11 and the second grinding disc 12 act on the ground and crushed ferrous sulfate to enter the screening space 1. The sulfuric acid screen is recovered.

[0049] Oxidation reaction step: the treated raw material is added with an oxidizing agent for stirring reaction.

[0050] The oxidizing agent in the oxidation reaction step includes sodium chlorate, hydrogen peroxide and oxygen.

[0051] Oxidation reaction step: ferrous sulfate and sulfuric acid are mixed by stirring. The mixing temperature is 30°C, the mixing time is 30 min, and the stirring speed is 90 r / min. The oxidizing agent is added for continuous stirring reaction, and the oxidizing agent is added in three times before reaching the reaction temperature. The stirring speed is increased by 40%, the reaction temperature is 110°C, and the reaction time is 55 min. The oxidizing agent adding process includes: the first time adding 70% of the mass of the oxidizing agent, the second time adding 20% of the mass of the oxidizing agent, and the third time adding 10% of the mass of the oxidizing agent.

[0052] Polymerization reaction step: the oxidized raw material is added with a polymerization agent for stirring reaction, and the polymerized raw material is dried after removing impurities to obtain a solid product.

[0053] The polymerization agent in the polymerization reaction step includes sodium hydroxide.

[0054] In the polymerization reaction step, the oxidized raw material is stirred, and the polymerization agent is slowly added during the stirring process. In the polymerization reaction step, the oxidized raw material is added with the polymerization agent, and the stirring reaction is alternately carried out at a fast and slow speed. In the polymerization reaction step, the stirring speed is 105 r / min, the reaction time is 25 min, and the reaction temperature is 80°C. By alternately carrying out slow and fast stirring, the stirring is sufficient, and the stirring speed and reaction time are reduced.

[0055] Second embodiment: The production process of the polymerized ferric sulfate includes the following steps: Raw material treatment step: the raw material is crushed and sieved.

[0056] In the raw material treatment step, the raw material includes ferrous sulfate and sulfuric acid. The first grinding disc 11 and the second grinding disc 12 act on the ferrous sulfate after being ground and crushed to enter the sieving space 1. The sulfuric acid is sieved and recovered.

[0057] Oxidation reaction step: the treated raw material is added with an oxidizing agent for stirring reaction.

[0058] The oxidizing agent in the oxidation reaction step includes sodium chlorate, hydrogen peroxide and oxygen.

[0059] Oxidation reaction step: ferrous sulfate and sulfuric acid are mixed by stirring. The mixing temperature is 35°C, the mixing time is 35 min, and the stirring speed is 90 r / min. The oxidant is added and the stirring reaction is continued. The oxidant is added in three times before the reaction temperature is reached. The stirring speed is increased by 55%, the reaction temperature is 115°C, and the reaction time is 60 min. The oxidant addition process includes: the first time to add 70% of the mass of the oxidant, the second time to add 20% of the mass of the oxidant, and the third time to add 10% of the mass of the oxidant.

[0060] Polymerization reaction step: after oxidation, the raw material is added to the polymerization agent for stirring reaction, and after polymerization, the impurities in the raw material are removed for drying treatment to obtain a solid product.

[0061] The polymerization agent in the polymerization reaction step includes sodium hydroxide.

[0062] In the polymerization reaction step, the oxidized raw material is stirred, and the polymerization agent is slowly added during the stirring process. In the polymerization reaction step, the oxidized raw material is added to the polymerization agent, and the stirring reaction is alternately carried out at a fast and slow speed. In the polymerization reaction step, the stirring speed is 110 r / min, the reaction time is 30 min, and the reaction temperature is 85°C. By alternately stirring at a slow and fast speed, the stirring is sufficient, and the stirring speed and reaction time are reduced.

[0063] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combination of the technical features does not exist, it should be considered as the scope of the present disclosure.

[0064] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of variations and improvements can be made, which are within the scope of the present application. Therefore, the scope of the present patent should be subject to the appended claims.

Claims

1. A process for the production of polyferric sulphate, characterized in that, The method comprises the following steps: The raw material processing step: the raw material is crushed and screened; The oxidation reaction step: the processed raw material is added with an oxidizing agent for stirring reaction; The polymerization reaction step: the oxidized raw material is added with a polymerization agent for stirring reaction, and the polymerized raw material is dried after removing impurities to obtain a solid product.

2. The process for producing polyferric sulfate according to claim 1, characterized in that, The raw material processing step includes ferrous sulfate and sulfuric acid; the oxidation reaction step includes sodium chlorate, hydrogen peroxide and oxygen; and the polymerization reaction step includes sodium hydroxide.

3. The process for producing polyferric sulfate according to claim 1, characterized in that, The polymerization reaction step further includes a testing step: detecting the iron content, salt base and pH value of the solid product; and the solid product is placed in a dry and ventilated environment after detection.

4. The process for producing polyferric sulfate according to claim 2, characterized in that, The raw material processing step: the ferrous sulfate is ground and crushed and then enters a screening space; a gas is injected into the screening space, and the gas blows up the light crushed ferrous sulfate for recycling; the sulfuric acid is screened and then recycled.

5. The process for producing polyferric sulfate according to claim 2, characterized in that, The oxidation reaction step: the ferrous sulfate and the sulfuric acid are mixed by stirring; the mixing temperature is 30-35℃, the mixing time is 30-35min, and the stirring speed is 90r / min; the oxidizing agent is added for continued stirring reaction; the stirring speed is increased by 40-55%, the reaction temperature is 110-115℃, and the reaction time is 55-60min.

6. The process for producing polyferric sulfate according to claim 2, wherein, The polymerization reaction step: the oxidized raw material is added with a polymerization agent, and the stirring reaction is alternately carried out at a fast speed and a slow speed.

7. The process for producing polyferric sulfate according to claim 6, characterized in that, The stirring speed in the polymerization reaction step is 105-110r / min, the reaction time is 25-30min, and the reaction temperature is 80-85℃.

Images