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CN-121974637-A - Road building material prepared from pure phosphogypsum and preparation method thereof

CN121974637ACN 121974637 ACN121974637 ACN 121974637ACN-121974637-A

Abstract

The application discloses a road construction material prepared from pure phosphogypsum and a preparation method thereof, and relates to the technical field of solid waste recycling and building materials, wherein the road construction material comprises, by mass, 85% -97% of phosphogypsum, 3% -15% of sulphoaluminate cement and 0.01% -5.0% of additive, wherein the sulphoaluminate cement is sulphoaluminate cement prepared by co-production of phosphogypsum by an phosphogypsum decomposition acid-making process, the additive is a stabilizer and/or an adhesive, the stabilizer is one or more of metakaolin, silica fume or fly ash, and the adhesive is a high-molecular polymer. The total amount of phosphogypsum of the application is approximately 100%, thereby realizing the real waste to be changed into valuable, and providing a revolutionary solution for the bulk consumption of phosphogypsum.

Inventors

  • ZOU DAQIN
  • LUO YI
  • HU QIGAO

Assignees

  • 贵州青昱科技有限公司

Dates

Publication Date
20260505
Application Date
20251224

Claims (7)

  1. 1. A road building material prepared from pure phosphogypsum is characterized by comprising, by mass, 85% -97% of phosphogypsum, 3% -15% of sulphoaluminate cement and 0.01% -5.0% of an additive, wherein the sulphoaluminate cement is produced by a phosphogypsum decomposition acid-making process.
  2. 2. A road construction material made of pure phosphogypsum according to claim 1, characterized in that the additive is a stabilizer and/or an adhesive, the stabilizer is one or more of metakaolin, silica fume or fly ash, and the adhesive is a high molecular polymer.
  3. 3. A road construction material made of pure phosphogypsum according to claim 2, characterized in that it is a road base material, an underlayment material or a road bed material; When used as a base material, the composite material comprises 85-90% of phosphogypsum, 10-15% of sulphoaluminate cement and 0.01-5% of additive; when used as a base layer material, the composite material comprises 90-94% of phosphogypsum, 6-10% of sulphoaluminate cement and 0.01-5% of additive; when used as roadbed material, the material consists of phosphogypsum 94-97 wt%, sulfoaluminate cement 3-6 wt% and additive 0.01-5 wt%.
  4. 4. A process for the preparation of a road construction material made of pure phosphogypsum according to any one of claims 1 to 3, comprising the steps of: (1) Pre-treating, namely crushing phosphogypsum and grinding the phosphogypsum to a preset fineness; (2) Preparing a curing agent, namely dry-mixing the sulphoaluminate cement and the additive to obtain the curing agent; (3) Mixing, namely mixing and stirring the phosphogypsum, the curing agent and water to obtain the mixture of the road construction material, wherein the addition amount of the water accounts for 5-8% of the total mass of the dry material.
  5. 5. The method of producing a road construction material from pure phosphogypsum according to claim 4, wherein in step (2), the optimal water content is determined by compaction test in the range of 12.0% -16.5%.
  6. 6. The method of producing a road construction material made of pure phosphogypsum as set forth in claim 5, wherein the step (2) further includes: (4) Paving and compacting, namely conveying the well-mixed road building material mixture to a construction site for paving and compacting; (5) And curing, namely performing moisture-preserving curing on the compacted structural layer to form a base layer, an underlayment or a roadbed of the road.
  7. 7. The method of producing a road construction material from pure phosphogypsum as claimed in claim 6, wherein the construction time of the road construction material mixture is up to 12 hours.

Description

Road building material prepared from pure phosphogypsum and preparation method thereof Technical Field The invention relates to the technical field of solid waste recycling and building materials, in particular to a road building material prepared from pure phosphogypsum and a preparation method thereof. Background Phosphogypsum is a large amount of industrial solid waste generated in the wet-process phosphoric acid production process, about 4-5 tons of phosphogypsum is generated per 1 ton of phosphoric acid produced, the annual discharge amount of phosphogypsum in China is huge, the historic stocking amount is large, but the comprehensive utilization rate is low, the phosphogypsum occupies land, serious threat is caused to the water body environment, and particularly huge pressure is caused to the ecological environment of the Yangtze river basin. At present, the utilization way of phosphogypsum is mainly limited to be used as a cement retarder or to produce building gypsum products, and the problems of limited consumption, low added value of products, high quality requirement and the like exist. The phosphogypsum is an important direction for realizing large-scale and high-value utilization of the phosphogypsum. However, the prior art generally adopts a system of phosphogypsum and ordinary Portland cement, and has two technical bottlenecks, namely, firstly, the ordinary Portland cement reacts with residual acidic impurities in phosphogypsum too quickly, so that the setting time of the mixture is short (usually only 4-6 hours), long-distance transportation and large-area construction are severely restricted, and secondly, the mixing amount of the ordinary Portland cement is usually more than 15 percent to achieve enough early strength, and the mixing amount of phosphogypsum is limited (usually less than 85 percent). There is a general technical prejudice in the art that phosphogypsum itself is considered to be low in activity and contains harmful impurities, and a large amount of ordinary portland cement or complex modification must be relied on to be used for roadbed materials. ‌ ‌ A Disclosure of Invention The invention aims to provide a road construction material made of pure phosphogypsum and a preparation method thereof, which are used for solving the problems in the background technology. The road construction material is prepared from the following raw materials, by mass, 85% -97% of phosphogypsum, 3% -15% of sulphoaluminate cement and 0.01% -5% of an additive, wherein the sulphoaluminate cement is produced by a phosphogypsum decomposition acid-making process. Further, the additive is a stabilizer and/or an adhesive, the stabilizer is one or more of metakaolin, silica fume or fly ash, and the adhesive is a high molecular polymer. Further, the road building material is a road base material, an underlayment material or a roadbed material; When used as a base material, the composite material comprises 85-90% of phosphogypsum, 10-15% of sulphoaluminate cement and 0.01-5% of additive; when used as a base layer material, the composite material comprises 90-94% of phosphogypsum, 6-10% of sulphoaluminate cement and 0.01-5% of additive; when the phosphogypsum is used as a roadbed material, the phosphogypsum accounts for 94% -97%, the sulphoaluminate cement accounts for 3% -6% and the additive accounts for 0.01% -5%. The preparation method of the road construction material made of pure phosphogypsum comprises the following steps: (1) Pre-treating, namely crushing phosphogypsum and grinding the phosphogypsum to a preset fineness; (2) Preparing a curing agent, namely dry-mixing the sulphoaluminate cement and the additive to obtain the curing agent; (3) Mixing, namely mixing and stirring the phosphogypsum, the curing agent and water to obtain the mixture of the road construction material, wherein the addition amount of the water accounts for 5-8% of the total mass of the dry material. Further, in the step (2), the optimal water content is determined by a compaction test, and the range is 12.0% -16.5%. Further, after the step (2), the method further comprises: (4) Paving and compacting, namely conveying the well-mixed road building material mixture to a construction site for paving and compacting; (5) And curing, namely performing moisture-preserving curing on the compacted structural layer to form a base layer, an underlayment or a roadbed of the road. Furthermore, the construction timeliness of the road construction material mixture can reach 12 hours. The application provides a road construction material prepared from pure phosphogypsum and a preparation method thereof, and has the advantages that the total consumption of the phosphogypsum is nearly 100%, the waste is changed into valuable in the real sense, a revolutionary solution is provided for large-scale phosphogypsum digestion, the setting time is controllable, the construction aging time is as long as 12 hours, the commercial production and the long-di