CN115073030A - Process for desulfurization and co-production of cement by using phosphogypsum - Google Patents

Process for desulfurization and co-production of cement by using phosphogypsum Download PDF

Info

Publication number
CN115073030A
CN115073030A CN202210826880.2A CN202210826880A CN115073030A CN 115073030 A CN115073030 A CN 115073030A CN 202210826880 A CN202210826880 A CN 202210826880A CN 115073030 A CN115073030 A CN 115073030A
Authority
CN
China
Prior art keywords
desulfurization
phosphogypsum
raw material
cement
production
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202210826880.2A
Other languages
Chinese (zh)
Other versions
CN115073030B (en
Inventor
李叶青
张克昌
余松柏
孙航
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huaxin Cement Co Ltd
Original Assignee
Huaxin Cement Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Huaxin Cement Co Ltd filed Critical Huaxin Cement Co Ltd
Priority to CN202210826880.2A priority Critical patent/CN115073030B/en
Publication of CN115073030A publication Critical patent/CN115073030A/en
Application granted granted Critical
Publication of CN115073030B publication Critical patent/CN115073030B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B7/00—Hydraulic cements
    • C04B7/36—Manufacture of hydraulic cements in general
    • C04B7/38—Preparing or treating the raw materials individually or as batches, e.g. mixing with fuel
    • C04B7/40—Dehydrating; Forming, e.g. granulating
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B7/00—Hydraulic cements
    • C04B7/02—Portland cement
    • C04B7/04—Portland cement using raw materials containing gypsum, i.e. processes of the Mueller-Kuehne type
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B7/00—Hydraulic cements
    • C04B7/24—Cements from oil shales, residues or waste other than slag
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B7/00—Hydraulic cements
    • C04B7/24—Cements from oil shales, residues or waste other than slag
    • C04B7/26—Cements from oil shales, residues or waste other than slag from raw materials containing flue dust, i.e. fly ash
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B7/00—Hydraulic cements
    • C04B7/36—Manufacture of hydraulic cements in general
    • C04B7/38—Preparing or treating the raw materials individually or as batches, e.g. mixing with fuel
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P40/00—Technologies relating to the processing of minerals
    • Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)

Abstract

The invention discloses a process for desulfurizing phosphogypsum and co-producing cement, which comprises the steps of obtaining phosphogypsum, drying, crushing, grinding, mixing with a ferro-silico-aluminum raw material according to a cement clinker with a low KH value, and grinding; the obtained low KH value mixture enters a desulfurizing furnace through a preheater, and a carbonaceous raw material is added for CaSO 4 The desulfurization of (2); cooling the obtained desulfurized material, adding a calcareous raw material, mixing and grinding to make the KH value of the desulfurized material meet the requirement of standard portland cement clinker; then the mixture enters a decomposing furnace to decompose carbonate; calcining the decomposed raw materials in a rotary kiln to prepare portland cement clinker; the mixed desulfurization with low KH value of the invention is adoptedThe method ensures that the desulfurization effect of the phosphogypsum at low temperature is good and stable, the desulfurization rate reaches more than 95 percent, and the problem of CaSO is solved 4 The CaS and other S-containing substances are difficult to desulfurize so as to cause adverse effect on subsequent calcination and application, so that the clinker can generate C in a large amount and stably 3 S mineral, SO in the Portland cement clinker 3 The content is not more than 3%.

Description

Process for desulfurization and co-production of cement by using phosphogypsum
Technical Field
The invention belongs to the technical field of building materials, and particularly relates to a process for desulfurizing phosphogypsum and co-producing cement.
Background
The phosphogypsum is a solid waste generated in a wet-process phosphoric acid process, the composition of the phosphogypsum is complex, besides calcium sulfate hydrate, incompletely decomposed phosphorite, residual phosphoric acid, fluoride, acid insoluble substances, organic matters and the like are also included, wherein the existence of fluorine and the organic matters has the greatest influence on the resource utilization of the phosphogypsum, the stacking occupies a large amount of land, and the water resource and the land resource are polluted. The recycling, safety and high-efficiency utilization of the phosphogypsum have important significance for solving the problems of environmental pollution and resource waste caused by stacking treatment.
The cement industry is one of the largest sources of carbon dioxide emissions in the world, accounting for 5-8% of the global emissions, of which 60% is derived from the calcination of limestone.
The phosphogypsum replaces limestone to be used as a CaO source to produce the cement clinker, which is a direction with challenge and significance for solving the resource utilization of the phosphogypsum, so that CaO in the clinker is mainly provided by the phosphogypsum, and the problem of carbon dioxide emission of the limestone in the cement production is reduced. Portland cement clinker pair SO widely applied in market 3 The content has stringent requirements, but CaSO 4 Relative to CaCO 3 In other words, it requires a higher temperature for complete decomposition and desulfurization, which increases the operational difficulties and costs of the process, and even remains in large quantities at the clinker calcination temperature, which certainly limits its application in the cement clinker production.
The factory building and production of sulfuric acid and co-production of cement by phosphogypsum in 1969 by Australian Linz company, and 7 sets of devices in 80 s of China, mainly comprises drying and dehydrating phosphogypsum, mixing with coke, clay, sand shale and the like according to the ratio of clinker, calcining in a hollow rotary kiln to obtain clinker, and calcining SO in kiln gas 2 The sulfuric acid is prepared after conversion and absorption. However, the strength of the phosphogypsum co-produced cement is generally lower, even the strength of the phosphogypsum co-produced cement does not reach 42.5 common Portland cementStrength grade and the like, and most of the co-production devices stop production at present.
In order to make the phosphogypsum meet the requirements of cement production and reduce the operation difficulty and energy consumption in the process, the phosphogypsum needs to be decomposed and desulfurized at a lower temperature. Many documents report researches on the decomposition of phosphogypsum by using carbonaceous raw materials, carbon monoxide atmosphere, elemental sulfur and the like, although the decomposition rate of the phosphogypsum can reach more than 99% under the low-temperature environment of 1000-1100 ℃, the realization of the desulfurization rate of more than 95% is difficult, the atmosphere needs to be stably and accurately regulated, the difficulty in the actual production process is increased undoubtedly, and if the desulfurization rate does not meet the requirement, the sulfur can be used as CaSO in the clinker sintering stage 4 The existing of CaS or solid solution substances, which leads to insufficient CaO and excessive existence of sulfur-containing substances in a system for producing cement clinker by taking phosphogypsum as a main CaO source, not only seriously affects C 3 The formation of S also has a number of adverse effects on the production and use of clinker.
How to realize the high-efficiency desulfurization of the phosphogypsum at low temperature becomes a technical problem to be solved urgently.
Disclosure of Invention
The invention aims to provide a process for desulfurizing phosphogypsum and co-producing cement, which realizes high-efficiency desulfurization of the phosphogypsum at low temperature and stably prepares C 3 High-quality portland cement clinker with high S content and low sulfur content.
In order to achieve the purpose, the technical scheme is as follows:
a process for desulfurization and co-production of cement by phosphogypsum comprises the following steps:
(1) obtaining phosphogypsum, drying, crushing, grinding, mixing with a ferro-silico-aluminum raw material according to a low KH value cement clinker, and grinding;
(2) the obtained low KH value mixture enters a desulfurizing furnace through a preheater, and a carbonaceous raw material is added for CaSO 4 The desulfurization of (2);
(3) cooling the obtained desulfurized material, adding a calcareous raw material, mixing and grinding to make the KH value of the desulfurized material meet the requirement of standard portland cement clinker; then the mixture enters a decomposing furnace to decompose carbonate;
(4) the decomposed raw material enters a rotary kiln to be calcined to prepare the portland cement clinker.
According to the scheme, SO in chemical components of phosphogypsum in the material preparation process in the step 1 3 The loss on ignition is calculated, and the remaining chemical components are measured in accordance with the substances mainly containing CaO.
According to the scheme, the aluminosilicoferrite raw material in the step 1 is one or more of sand shale, coal gangue, silica, clay, fly ash and various waste residues.
According to the scheme, the low KH value in the step 1 is 0.60-0.70.
According to the scheme, the carbonaceous raw material in the step 2 is one or more of common coal, high-sulfur coal and coke; c in carbonaceous raw material and SO in phosphogypsum 3 Is 0.6 to 1.5.
According to the scheme, in the step 2, the desulfurization furnace creates a reducing atmosphere through the carbonaceous raw materials and the introduced tertiary air, and the volume concentration of CO in the desulfurization furnace is controlled to be 2-6%.
According to the scheme, the desulfurization temperature of the desulfurization furnace in the step 2 is 1000-1100 ℃.
According to the scheme, the calcareous raw material in the step 3 is a raw material taking CaO as a main component; specifically one or mixture of limestone, quicklime and slaked lime.
According to the scheme, the KH value in the step 3 is 0.80-0.95.
According to the scheme, the calcination temperature of the rotary kiln in the step 4 is 1300-1450 ℃.
According to the scheme, C in mineral composition of the portland cement clinker obtained in step 4 3 30% -65% of S and C 2 S is 10% -50%, C 3 A is 0% -10%, C 4 AF 5% -15%, CaSO 4 0% -5% of the total amount of the components and 0% of CaS.
The design of firstly desulfurizing with low KH value and then supplementing calcium comes from systematic research findings of the inventor on phosphogypsum decomposition and desulfurization. Research shows that except the necessary C (coal), other components in the ingredients are arranged into SiO according to the sequence beneficial to phosphogypsum decomposition 2 ＞Fe 2 O 3 ＞Al 2 O 3 。
Due to C 2 S can be formed in large quantities at 1000-1100 ℃ and SiO 2 Has higher ratio in cement clinker, thus SiO 2 Most favoured by CaSO 4 Conversion of CaS to CaO and subsequent incorporation of SiO 2 Form C 2 And S, thereby stably and efficiently desulfurizing. SiO such as silica fume and rice husk ash 2 The highly reactive starting material also favors CaSO by this mechanism 4 And stably desulfurizing the CaS at low temperature.
Fe 2 O 3 Itself to CaSO 4 The decomposition effect is smaller, and instead, the CaSO is reduced with C 4 There is a conflict, but in the presence of SiO 2 In the presence of Fe 2 O 3 4CaO xAl is formed 2 O 3 ·Fe 2 O 3 Plays a role in promoting SiO 2 Combined with CaO, laterally promotes CaSO 4 And the direction of CaS to CaO.
Al 2 O 3 Will promote CaSO from the side 4 Decomposition in the direction of CaO, but when CaSO 4 When decomposed to a certain degree, CaSO is inhibited 4 Is mainly due to Al 2 O 3 Binding to CaSO 4 Form 3 CaO.3Al after reacting with CaO 2 O 3 ·CaSO 4 On the other hand, Al 2 O 3 Will also directly react with C 2 S combines to form 2 CaO. SiO 2 ·Al 2 O 3 Thereby not playing a role of desulfurization, and striving for CaO in the system when the clinker is calcined at high temperature, if the CaSO is realized at low temperature 4 High decomposition rate and desulfurization rate of Al in total 2 O 3 Is harmful.
Flux and Fe 2 O 3 Has similar functions and can promote SiO 2 Combined with CaO, promotes CaSO laterally 4 And the direction of CaS to CaO. The phosphogypsum contains a small amount of F, P fluxing elements and the like, and the addition of the fluxing agent can lead to the melting phenomenon of clinker, thus being unfavorable for production, so the addition of the fluxing agent is basically not needed.
Compared with the prior art, the invention has the following beneficial effects:
by adopting the low KH value mixed desulfurization method, the desulfurization effect of the phosphogypsum at low temperature is good and stable, the desulfurization rate reaches more than 95 percent, and the problem of CaSO is solved 4 The CaS and other S-containing substances are difficult to desulfurize so as to cause adverse effects on the calcination and the application of the rear-end portland cement clinker, so that the clinker can generate C in a large amount and stably 3 S mineral, and SO in the produced portland cement clinker 3 The content is not more than 3 percent, the appearance and the mineral composition of the clinker are completely consistent with those of the clinker prepared by adopting limestone as a full CaO source, and the breakthrough of producing high-quality portland cement clinker by utilizing a large amount of solid waste phosphogypsum is realized.
The phosphogypsum can be effectively utilized, CaO in the portland cement clinker is mainly provided by the phosphogypsum, wherein the percentage of the CaO provided by the phosphogypsum in the total CaO content is more than 65%, and the problem of carbon dioxide emission caused by limestone is reduced while the phosphogypsum is utilized for solid waste.
Drawings
FIG. 1: the invention relates to a process flow chart of ardealite desulfurization and cement co-production.
FIG. 2: XRD pattern of material after high and low KH value desulfurization.
FIG. 3: the XRD pattern of the portland cement clinker obtained in comparative example 1.
FIG. 4: comparative examples 2, 3 and examples 1, 2, 3 XRD patterns of portland cement clinker were obtained at 1325 ℃.
FIG. 5: comparative examples 2, 3 and examples 1, 2, 3 XRD patterns of portland cement clinker obtained at 1400 ℃.
Detailed Description
The following examples further illustrate the technical solutions of the present invention, but should not be construed as limiting the scope of the present invention.
The specific embodiment provides a process for desulfurization and co-production of cement by phosphogypsum, which is shown in the attached drawing 1:
(1) obtaining phosphogypsum, drying, crushing, grinding, mixing with a ferro-silico-aluminum raw material according to a cement clinker with a low KH value, and grinding;
(2) the obtained low KH value mixture is pretreatedThe hot water enters a desulfurizing furnace, and a carbonaceous raw material is added for CaSO 4 The desulfurization of (2);
(3) cooling the obtained desulfurized material, adding a calcareous raw material, mixing and grinding to make the KH value of the desulfurized material meet the requirement of standard portland cement clinker; then the mixture enters a decomposing furnace to decompose carbonate;
(4) the decomposed raw material enters a rotary kiln to be calcined to prepare the portland cement clinker.
Specifically, SO in chemical components of phosphogypsum in the proportioning process in the step 1 3 The loss on ignition is calculated, and the remaining chemical components are measured in accordance with the substances mainly containing CaO. The low KH value is 0.60-0.70.
Specifically, the aluminosilicoferrite raw material in the step 1 is one or more of sand shale, coal gangue, silica, clay, fly ash and various waste residues.
Specifically, the carbonaceous raw material in the step 2 is one or more of common coal, high-sulfur coal and coke; c in carbonaceous raw material and SO in phosphogypsum 3 Is 0.6 to 1.5. The desulfurization furnace creates a reducing atmosphere by the carbonaceous raw material and the introduced tertiary air, and the volume concentration of CO in the desulfurization furnace is controlled to be 2-6%; the desulfurization temperature is 1000-1100 ℃.
Specifically, the calcareous raw material in the step 3 is a raw material with CaO as a main component; specifically one or a mixture of limestone, quicklime and hydrated lime. The standard portland cement clinker has a KH value of 0.80-0.95.
Specifically, the calcination temperature of the rotary kiln in the step 4 is 1300-1450 ℃; in the mineral composition of the obtained portland cement clinker C 3 30% -65% of S and C 2 S is 10% -50%, C 3 A is 0% -10%, C 4 AF 5% -15%, CaSO 4 0% -5% of the total amount of the components and 0% of CaS.
Raw material acquisition and detection in the following specific examples:
the method comprises the steps of obtaining phosphogypsum and silicon-aluminum-iron raw materials, drying, crushing and grinding the raw materials, and then analyzing chemical components, wherein the chemical components of a batch of phosphogypsum, coal gangue, iron ore soil and fly ash are randomly obtained and are shown in the table 1:
TABLE 1 analysis of chemical composition
Name (R) Loss on ignition SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 K 2 O Na 2 O
Phosphogypsum 20.04 6.04 0.30 0.28 29.75 0.02 42.28 0.22 0.12
Coal gangue 4.63 76.3 6.62 4.64 1.91 2.35 0.48 1.34 0.55
Iron ore soil 3.27 48.9 15.55 15.9 7.56 4.41 0.01 0.78 2.79
Fly ash 5.33 43.41 32.88 6.44 6.72 0.7 1.2 0.81 0.47
The carbonaceous feedstocks used were subjected to conventional analysis and chemical composition analysis of the ash, here high sulfur coal, with the results shown in tables 2 and 3, respectively:
TABLE 2 conventional analysis of high sulfur coal
Name (R) Moisture content Ash content Volatile component Fixed carbon content All sulfur Qnet,ad Qnet,d
High sulfur coal 1.42 23.48 10.25 64.85 2.99 25.25 26.33
TABLE 3 chemical composition analysis of ash content of high-sulfur coal
Name (R) Loss on ignition SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 K 2 O Na 2 O
Ash content of coal 0 47.36 26.12 15.21 4.16 1.55 2.11 1.03 0.40
Examples 1, 2 and 3
1. Low KH ratio design
SO in chemical components of phosphogypsum 3 Calculating the loss on ignition of the ardealite, wherein the loss on ignition is 20.04% + 42.28% + 62.32%, the rest chemical components are measured corresponding to substances mainly containing CaO, the limestone is used similarly, and the raw materials are mixed with a ferro-silico-aluminum raw material and a carbonaceous raw material according to a cement clinker with a low KH value, wherein the carbonaceous raw material adopts high-sulfur coal, and the high-sulfur coal is mixed with SO in the ardealite according to a fixed carbon content 3 The molar ratio of the phosphorus-containing compound to the sulfur-containing compound is 0.8, namely the dosage of the high-sulfur coal is equal to that of the phosphogypsum
0.4228 0.8 12/(80 0.6485), wherein the ferro-silico-aluminum raw material adopts coal gangue, iron ore soil and fly ash, and finally adopts phosphogypsum in weight ratio: coal gangue: iron ore soil: fly ash: the high-sulfur coal is 89: 2: 7: 2: 6.96, the weight of ash introduced by the high-sulfur coal is 6.96 × 0.2348 ═ 1.63, and the proportioning and theoretical mineral composition are shown in tables 4 and 5 respectively:
TABLE 4 proportions
Name (R) Loss on ignition SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 K 2 O Na 2 O Proportioning
Phosphogypsum 62.32 6.04 0.30 0.28 29.75 0.02 0 0.22 0.12 89
Coal gangue 4.63 76.3 6.62 4.64 1.91 2.35 0.48 1.34 0.55 2
Iron ore soil 3.27 48.9 15.55 15.9 7.56 4.41 0.01 0.78 2.79 7
Fly ash 5.33 43.41 32.88 6.44 6.72 0.7 1.2 0.81 0.47 2
Ash content of coal 0 47.36 26.12 15.21 4.16 1.55 2.11 1.03 0.40 1.63
TABLE 5 theoretical mineral composition
KH SM IM C 3 S C 2 S C 3 A C 4 AF CaSO 4
0.666 2.717 1.404 -0.22 75.16 8.11 12.18 0.26
KH of this low KH ratio is 0.666, and C is used as main mineral phase 2 S is dominant and has no C 3 S。
2. Desulfurization of phosphogypsum
Mixing and grinding the phosphogypsum, the coal gangue, the iron ore soil and the fly ash which are measured according to the proportion, and then entering a desulfurization furnace through a preheater for CaSO 4 The desulfurization is carried out, the desulfurization furnace creates a reducing atmosphere by adding metered high-sulfur coal and introducing tertiary air, the temperature of the desulfurization furnace is set to 1080 ℃, and SO is measured by full-sulfur analysis of the desulfurized material 3 The content was 2.2%.
It should be noted here that the speed or the gas amount of the tertiary air introduced into the desulfurization furnace is influenced by the process and the equipment, and in order to achieve a suitable atmosphere condition, it is necessary to evaluate and adjust the result of the total sulfur analysis and detection of the desulfurized material, and the smaller the total sulfur content is, the better, the volume concentration of CO in the desulfurization furnace is controlled to be 4% in this example.
3. Adding calcium material to raise KH value
Adding a calcareous raw material into the desulfurized material for mixing and grinding, wherein the calcareous raw material is limestone, and the analysis result of the chemical components is shown in table 6:
TABLE 6 chemical composition analysis of limestone
Name (R) Loss on ignition SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 K 2 O Na 2 O
Limestone 39.84 5.66 1.29 1.02 48.33 2.64 0.05 0.29 0.15
The added limestone is blended by the total weight percentage of the phosphogypsum, coal gangue, iron ore soil, fly ash and high-sulfur coal, for example, if 19% of limestone is blended, the weight of the added limestone is (89+2+7+2+6.96) × 19% — 20.32.
The design of 3 different KH values was carried out using 3 different amounts of limestone added as examples, and the theoretical mineral compositions obtained are shown in table 7:
table 7 examples of blending different amounts of limestone
Item Doped limestone KH SM IM C 3 S C 2 S C 3 A C 4 AF CaSO 4
Example 1 19％ 0.861 2.691 1.390 50.13 27.05 6.99 10.70 0.23
Example 2 22％ 0.889 2.688 1.388 56.21 21.25 6.86 10.52 0.23
Example 3 25％ 0.916 2.684 1.386 61.90 15.81 6.73 10.35 0.23
The KH values of the examples were 0.861, 0.889 and 0.916, respectively.
Powder which is mixed with different amounts of limestone and ground enters a decomposing furnace through a preheater to decompose carbonate.
4. Calcination of clinker
The decomposed raw materials were calcined in a rotary kiln set at 1325 c and 1400 c, i.e., two temperatures for each example, to produce portland cement clinker.
Comparative examples 1, 2 and 3
The high-sulfur coal is also mixed with SO in phosphogypsum according to the fixed carbon content 3 The molar ratio of the calcium-containing raw materials is 0.8, the calcium-containing raw materials are respectively doped with 13% (comparative example 1), 19% (comparative example 2) and 25% (comparative example 3) limestone to improve KH, and the rest is the same as the examples 1, 2 and 3, wherein the KH is 0.764 (the weight ratio of phosphogypsum to coal gangue to iron ore soil to fly ash to high-sulfur coal is 91: 1: 6: 2: 7.12).
Comparison of the desulfurization effect under otherwise identical conditions between a low KH of 0.666 (examples 1, 2, 3) and a KH of 0.764 (comparative examples 1, 2, 3), total sulfur analysis determined SO for the desulfurized feed of example KH of 0.666 3 The SO content of the desulfurized material was 2.2% for comparative example KH, which is 0.764 3 The content was 7.4%. Theoretical mineral composition is shown in Table 8, XRD pattern is shown in FIG. 2, and CaSO in combination with KH of 0.666 4 And a peak containing sulfur of substantially less than 0.764 of KH, and C 2 The peak of S is more pronounced, which further indicates that the lower KH ratio results in better desulfurization.
TABLE 8 theoretical mineral composition of the proportions used for desulfurization in step 2
Item KH SM IM C 3 S C 2 S C 3 A C 4 AF CaSO 4
Comparative example 0.764 2.710 1.444 27.07 49.32 7.83 11.16 0.25
Examples 0.666 2.717 1.404 -0.22 75.16 8.11 12.18 0.26
The theoretical mineral composition of the comparative example and example with limestone addition is shown in table 9, the percentage of CaO in the raw materials in total CaO content is shown in table 10, the XRD patterns of the clinker produced at 1325 ℃ and 1400 ℃ in the comparative example 1 are shown in fig. 3, and the XRD patterns of the clinker produced at 1325 ℃ and 1400 ℃ in the comparative examples 2 and 3 and examples 1, 2 and 3 are shown in fig. 4 and 5, respectively, and the formation of each clinker mineral is good. The method of firstly desulfurizing with low KH value and then supplementing calcium to increase KH value is adopted in both the comparative example and the embodiment of the invention, so that C is ensured 3 S can be formed in a large amount and stably at 1325 ℃; the CaO provided by the phosphogypsum accounts for more than 65 percent of the total CaO content, so the CaO in the silicate cement clinker prepared by the invention is mainly provided by the phosphogypsum; CaSO in examples 1, 2 and 3 4 Is much lower than in comparative examples 1, 2, 3, its CaSO 4 Is very small, SO is measured 3 The content is less than or equal to 3 percent, while the CaSO in the comparative examples 1, 2 and 3 4 And the peak containing sulfur was higher than those of examples 1, 2 and 3, which are CaSO 4 Higher content of SO 3 SO content of 6% -12% in comparative examples 1, 2, 3 3 The content can not meet the requirements of the cement industry; comparative example 1 with minimum limestone addition and CaSO 4 Is lower than in comparative examples 2 and 3, but the peak containing sulfur is relatively high, and in the comparative example, as the content of the doped limestone is increased, the unknown mineral represented by the peak containing sulfur is decomposed to release SO 3 Combined with CaO supplied from limestone to form CaSO 4 So that CaSO 4 Further confirms the unknown peak (and C) 2 S-side peaks overlap) are indeed sulfur-containing species, it can also be observed in fig. 4, 5 that the sulfur-containing peaks in comparative examples 2, 3 are significantly higher than in examples 1, 2, 3; in comparative example 1, KH reached 0.908, but C was added 3 The peak of S is significantly lower thanExamples 1, 2 and 3, and examples 1, 2 and 3, in which the KH value after limestone supplementation was much lower than that in comparative examples 2 and 3, C was determined 3 The formation of S can be close to that of comparative examples 2 and 3, i.e. the comparative examples are prepared with the same content of C 3 The clinker of S needs higher KH value and more CaO as cost; the phenomena further show that the ardealite has good desulfurization effect due to the low KH ratio, thereby bringing more advantages for the subsequent preparation of silicate clinker.
TABLE 9 theoretical mineral composition spiked with different amounts of limestone
Item Doped limestone KH SM IM C 3 S C 2 S C 3 A C 4 AF CaSO 4
Comparative example 1 13％ 0.908 2.691 1.430 60.50 17.34 7.03 10.21 0.23
Comparative example 2 19％ 0.968 2.683 1.424 72.61 5.76 6.75 9.87 0.22
Comparative example 3 25％ 1.025 2.675 1.419 83.17 -4.35 6.50 9.57 0.22
Example 1 19％ 0.861 2.691 1.390 50.13 27.05 6.99 10.70 0.23
Example 2 22％ 0.889 2.688 1.388 56.21 21.25 6.86 10.52 0.23
Example 3 25％ 0.916 2.684 1.386 61.90 15.81 6.73 10.35 0.23
TABLE 10 percentage of CaO in the raw materials to the total CaO content
Figure BDA0003744306120000081
The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.

Claims (10)

1. The process for desulfurization and co-production of cement by using phosphogypsum is characterized by comprising the following steps:
(1) obtaining phosphogypsum, drying, crushing, grinding, mixing with a ferro-silico-aluminum raw material according to a cement clinker with a low KH value, and grinding;
(2) the obtained low KH value mixture enters a desulfurizing furnace through a preheater, and a carbonaceous raw material is added for CaSO 4 The desulfurization of (2);
(3) cooling the obtained desulfurized material, adding a calcareous raw material, mixing and grinding to make the KH value of the desulfurized material meet the requirement of standard portland cement clinker; then the mixture enters a decomposing furnace to decompose carbonate;
(4) the decomposed raw material enters a rotary kiln to be calcined to prepare the portland cement clinker.
2. The process for desulfurization and co-production of cement by phosphogypsum as claimed in claim 1, wherein the raw material of silico-aluminoferrite in step 1 is one or more of sand shale, coal gangue, silica, clay, fly ash and various waste residues.
3. The process for the desulfurization and co-production of cement with phosphogypsum as claimed in claim 1, wherein the low KH value in step 1 is 0.60-0.70.
4. The phosphogypsum desulfurization and cement co-production process as claimed in claim 1, wherein the carbonaceous raw material in step 2 is one or more of common coal, high sulfur coal and coke; c in carbonaceous raw material and SO in phosphogypsum 3 Is 0.6 to 1.5.
5. The process for desulfurization and CO-production of cement by phosphogypsum as claimed in claim 1, wherein in the step 2, the desulfurization furnace creates a reducing atmosphere by carbonaceous raw materials and tertiary air, and the volume concentration of CO in the desulfurization furnace is controlled to be 2% -6%.
6. The process for desulfurization and co-production of cement by phosphogypsum as claimed in claim 1, wherein the desulfurization temperature of the desulfurization furnace in step 2 is 1000-1100 ℃.
7. The process for desulfurization and co-production of cement by phosphogypsum as claimed in claim 1, wherein the calcareous raw material in step 3 is a raw material with CaO as a main component; specifically one or mixture of limestone, quicklime and slaked lime.
8. The process for the desulfurization and co-production of cement with phosphogypsum as claimed in claim 1, wherein the KH value in step 3 is 0.80-0.95.
9. The process for desulfurization and co-production of cement by phosphogypsum as claimed in claim 1, wherein the calcination temperature of the rotary kiln in the step 4 is 1300-1450 ℃.
10. The process for desulfurization and co-production of cement by phosphogypsum as claimed in claim 1, wherein the mineral composition of the portland cement clinker obtained in step 4 is C 3 30% -65% of S and C 2 S is 10% -50%, C 3 A is 0% -10%, C 4 AF 5% -15%, CaSO 4 0% -5% of the total amount of the components and 0% of CaS.
CN202210826880.2A 2022-07-13 2022-07-13 Process for desulfurization and co-production of cement by using phosphogypsum Active CN115073030B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210826880.2A CN115073030B (en) 2022-07-13 2022-07-13 Process for desulfurization and co-production of cement by using phosphogypsum

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210826880.2A CN115073030B (en) 2022-07-13 2022-07-13 Process for desulfurization and co-production of cement by using phosphogypsum

Publications (2)

Publication Number Publication Date
CN115073030A true CN115073030A (en) 2022-09-20
CN115073030B CN115073030B (en) 2023-03-14

Family

ID=83258907

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210826880.2A Active CN115073030B (en) 2022-07-13 2022-07-13 Process for desulfurization and co-production of cement by using phosphogypsum

Country Status (1)

Country Link
CN (1) CN115073030B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115504495A (en) * 2022-10-21 2022-12-23 华新水泥股份有限公司 Method for decomposing phosphogypsum by recycling tail gas

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0957052A (en) * 1995-08-21 1997-03-04 Kyoei Kogyo Kk Desulfurizing and denitrificating device utilizing ready-mixed concrete sludge and waste construction material
CN101003422A (en) * 2007-01-17 2007-07-25 贵州大学 New method for producing sulfuric acid and cement by using phosphogypsum
CN101343047A (en) * 2008-08-26 2009-01-14 山东鲁北企业集团总公司 Improved preparation technique for preparing sulphuric acid and cement with gypsum
CN108892401A (en) * 2018-08-23 2018-11-27 天津水泥工业设计研究院有限公司 A kind of method and clinker of ardealite calcining belite sulphoaluminate cement clinker
CN111233357A (en) * 2020-03-18 2020-06-05 天津水泥工业设计研究院有限公司 Industrial production method for preparing sulphoaluminate cement clinker and co-producing sulfuric acid by using total solid wastes

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0957052A (en) * 1995-08-21 1997-03-04 Kyoei Kogyo Kk Desulfurizing and denitrificating device utilizing ready-mixed concrete sludge and waste construction material
CN101003422A (en) * 2007-01-17 2007-07-25 贵州大学 New method for producing sulfuric acid and cement by using phosphogypsum
CN101343047A (en) * 2008-08-26 2009-01-14 山东鲁北企业集团总公司 Improved preparation technique for preparing sulphuric acid and cement with gypsum
CN108892401A (en) * 2018-08-23 2018-11-27 天津水泥工业设计研究院有限公司 A kind of method and clinker of ardealite calcining belite sulphoaluminate cement clinker
CN111233357A (en) * 2020-03-18 2020-06-05 天津水泥工业设计研究院有限公司 Industrial production method for preparing sulphoaluminate cement clinker and co-producing sulfuric acid by using total solid wastes

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115504495A (en) * 2022-10-21 2022-12-23 华新水泥股份有限公司 Method for decomposing phosphogypsum by recycling tail gas

Also Published As

Publication number Publication date
CN115073030B (en) 2023-03-14

Similar Documents

Publication Publication Date Title
CN115180846B (en) Process for preparing calcium sulphoaluminate modified portland cement clinker by phosphogypsum desulfurization
CN100513341C (en) Method for producing cement and vitriol from high silicon ardealite
CN109053006B (en) Sulphoaluminate cement clinker taking tungsten tailings as raw material and preparation method thereof
CN107056100A (en) A kind of preparation method of clinker
CN101003422A (en) New method for producing sulfuric acid and cement by using phosphogypsum
CN115073030B (en) Process for desulfurization and co-production of cement by using phosphogypsum
CN113354311A (en) Resource-saving low-carbon cement clinker and preparation method thereof
CN1294181A (en) Clean combustion of coal and application and products of its companion substance
CN112299734A (en) Method for regulating and controlling alite crystal structure in cement clinker
CN101575180B (en) Strontium-barium cement calcination composite mineralizer
CN115093135B (en) Process for preparing belite sulphoaluminate cement clinker by phosphogypsum desulfurization
CN101357773B (en) Method for reducing ardealite decomposition temperature
CN107162447A (en) A kind of method that utilization carbide slag prepares clinker
CN101671131A (en) Method for co-producing cement, sulfuric acid and gypsum by using lead-zinc tailings and acid-leaching electrolytic manganese residues as main raw materials
CN115286266B (en) Carbon-negative clinker prepared from phosphogypsum and preparation method of carbon-negative clinker
CN115108744A (en) Process for decomposing phosphogypsum and co-producing cement
CN1696073A (en) Method for producing sulfuric acid associated with high Belite cement through anhydrite
CN112250051B (en) Method for co-producing phosphoric acid and cement clinker by absorbing phosphogypsum roasting smoke by phosphorite slurry
KR100806645B1 (en) Composition of clinker and method for preparing thereof
EP4385961A1 (en) Method of producing cement clinker from a source of calcium sulfate
CN115504692B (en) Method for preparing carbonized cementing material and co-producing sulfuric acid by using semi-dry desulfurization ash
CN116553842B (en) High-magnesium low-carbon cement clinker and preparation method thereof
CN103864023A (en) Method for reducing and decomposing ardealite by using ardealite carbonatation tail gas
CN116199437A (en) Method for realizing high desulfurization rate of phosphogypsum and preparing low-carbon cement clinker
KR102609899B1 (en) Additive for Cement Clinker Using the Hydrochloric Sludge and Manufacturing Method Thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant