A mineral processing method for efficiently recovering barite from thermally treated drilling waste

Abstract

The present invention discloses a mineral processing method for efficiently recovering barite from heat-treated drilling waste, comprising the following steps: (1) wet-screening and classifying the drilling waste containing barite; (2) magnetically separating the undersize product to obtain a magnetic product and a non-magnetic product; (3) performing a roughing separation and a fine separation on the non-magnetic product to obtain a barite powder product 1; and (4) scavenging the roughing tailings three times, combining the scavenged concentrates, and then fine separation twice to obtain a barite powder product 2. The present invention adopts a mineral processing method to efficiently recover barite from heat-treated drilling waste, and obtains two barite powder products of different grades, both of which can be recycled as drilling fluid raw materials, thereby realizing resource utilization of waste and reducing environmental hazards.

Description

Technical Field

[0001] The present invention relates to the field of mineral processing, and in particular to a mineral processing method for efficiently recovering barite from heat-treated drilling waste. Background Art

[0002] Drilling waste is composed of various components generated during the drilling process, including drilling cuttings, oil, and drilling fluid. Barite is often used as a weighting agent in drilling fluid to increase its density. my country generates a significant amount of drilling waste annually. If not properly handled, it can pose significant risks to soil, groundwater, and other resources. Furthermore, drilling waste contains valuable components such as barite, making its resource utilization crucial. Current treatment methods for drilling waste include solidification, backfilling, thermal treatment, and biological treatment. Thermal treatment involves heating the waste to the distillation or cracking temperature (200-1000°C) of the oil in the waste under anaerobic conditions and maintaining this temperature until all the oil is separated. The distilled oil can be processed into products, and the oil-free solids are further treated using solidification technology, a technology widely used in China for the harmless treatment of oily sludge.

[0003] Currently, research on the recovery of barite mainly focuses on untreated drilling waste, and there is little research on the efficient recovery of barite from heat-treated drilling waste using mineral processing methods. After high-temperature heat treatment, the physical composition and structure of drilling waste will undergo significant changes, and the process required to recover barite is also quite different from that before treatment. Patent CN114029155A discloses a mineral processing method for recovering weighting agents from drilling fluids through gravity separation. The barite concentrate product is obtained by a combined classification-gravity separation-flotation method, but the recovery rate is only about 50%. Patent CN214299978U discloses a barite drilling weighting agent recovery device. The barite drilling weighting agent is obtained through high-temperature calcination, oxidation-reduction, precipitation and washing operations. Under the same conditions, the product performance is better than that of ordinary barite weighting agents, but there are disadvantages of high energy consumption and complex process. Patent CN116060205A discloses a process for recovering barite from the residual solid phase of thermal desorption of drilling oil-based cuttings. A special physical purification method is used to obtain a barite product that meets the enterprise Class II standard. The process uses nanobubbles for flotation, and the bubble diameter is difficult to accurately control during actual production. Summary of the Invention

[0004] The object of the present invention is to provide a beneficiation method for efficiently recovering barite from heat-treated drilling waste. The method uses beneficiation means to comprehensively utilize the potential secondary resource of heat-treated drilling waste, which not only reduces environmental hazards, but also both of the obtained two barite products can be used for recycling as drilling fluid weighting agents, thereby improving resource utilization efficiency.

[0005] The present invention provides a beneficiation method for efficiently recovering barite from heat-treated drilling waste, comprising the following steps:

[0006] S1. Wet screening and classifying the drilling waste to obtain undersize products and tailings;

[0007] S2. Magnetic separation is performed on the undersize product obtained in step S1 to obtain a magnetic product and a non-magnetic product;

[0008] S3. The non-magnetic product obtained in step S2 is subjected to a roughing process to obtain a roughing concentrate and roughing tailings;

[0009] S4. The rougher concentrate obtained in step S3 is subjected to a beneficiation step to obtain a barite powder product 1;

[0010] S5. The rougher tailings obtained in step S3 are scavenged three times, and the scavenged concentrates obtained from the three scavengings are combined and then scavenged twice to obtain a barite powder product 2.

[0011] Furthermore, in step S1, the drilling waste components include barite, hematite, quartz, calcite, lime, etc.

[0012] Furthermore, in the wet sieving classification in step S1, the sieve hole size is 38-74 μm.

[0013] Furthermore, in step S2, the magnetic separation frame concentration is 20% to 30%, the magnetic field strength is 2000 to 4000 Gs, and the obtained magnetic separation product is used as tailings.

[0014] Furthermore, the mass concentration of mineral solid particles in the flotation pulp in all flotation processes in steps S3 to S5 is 25% to 35%.

[0015] Furthermore, the roughing agent system described in step S3 is as follows: the pH adjuster is dilute hydrochloric acid, and the pH of the slurry is adjusted to 8-9; the dispersant is sodium carbonate, and the dosage is 300-600 g / t; the inhibitor is a combination of sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 600-1200 g / t; the collector is a combination of sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate:benzohydroxamic acid:coconut amine is (150-200):(15-30):1, and the dosage is 800-1000 g / t.

[0016] Furthermore, the selection in step S4 is selection 1, specifically, an inhibitor and a collector are added in sequence; the inhibitor is a combination of sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the amount used is 400-800 g / t; the collector is a combination of sodium oleate, benzohydroxamic acid, and cocamide, wherein the mass ratio of sodium oleate:benzohydroxamic acid:cocamide is (150-200):(15-30):1, and the amount used is 200-300 g / t; the selected tailings are returned to the roughing step, and the selected concentrate is used as the barite powder product 1.

[0017] Furthermore, step S5 includes the following steps:

[0018] The roughing tailings in step S3 are subjected to three scavenging operations, including scavenging one, scavenging two, and scavenging three; the dosage of the reagents for the three scavenging operations is the same, specifically: the inhibitor is a combination of sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 500-800 g / t; the collector is a combination of sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate:benzohydroxamic acid:coconut amine is (150-200):(15-30):1, and the dosage is 200-400 g / t; the scavenging tailings obtained in the scavenging one are subjected to scavenging two, and the scavenging tailings obtained in the scavenging two are subjected to scavenging three, and the scavenging tailings obtained in the scavenging three are subjected to tailings treatment;

[0019] The scavenged concentrates obtained from the three scavenging steps are combined for two concentrations, namely concentration 2 and concentration 3; only inhibitors are used in the reagent system of concentration 2, while the inhibitor used in concentration 2 is a combination of sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 300-500g / t; blank flotation is performed in concentration 3; the concentrate obtained from concentration 3 is used as barite powder product 2.

[0020] Step S5 also includes a scavenging, which is scavenging 4; scavenging 4 uses the tailings of the selection 2 as the flotation object, and only adds a collector. The collector used in scavenging 4 is a combination of sodium oleate, benzohydroxamic acid, and cocamide, wherein the mass ratio of sodium oleate: benzohydroxamic acid: cocamide is (150-200): (15-30): 1, and the dosage is 100-200 g / t; the scavenged concentrate obtained by scavenging 4 is combined with the selected tailings obtained by selection 3 and returned to selection 2; the scavenged tailings obtained by scavenging 4 are used for tailings treatment.

[0021] Principle of the present invention:

[0022] The collector used in barite flotation is composed of sodium oleate, benzohydroxamic acid and coconut amine. Sodium oleate has good collecting performance and chemically adsorbs on the surface of barite to make it hydrophobic and float. It also has foaming properties, so there is no need to add a separate foaming agent. Benzohydroxamic acid can react with Ba on the surface of barite. 2+ It forms a chelate structure, thus having strong selectivity. When used in combination with sodium oleate, it can effectively improve the gangue entrainment phenomenon and make up for the poor selectivity of sodium oleate. Cocoamine mainly plays an emulsifying role, avoiding the formation of micelles between sodium oleate molecules in the collector, and at the same time is beneficial to the dispersion of the collector in the slurry, so that its interaction with the mineral is more sufficient.

[0023] The inhibitor used in barite flotation is composed of sodium silicate and tannic acid. The HSiO3- ions formed by sodium silicate in the pulp can have a good inhibitory effect on quartz and other silicate gangue minerals; tannic acid contains more hydroxyl and carboxyl groups, which can effectively inhibit gangue minerals such as calcite and hematite.

[0024] Beneficial effects of the present invention:

[0025] (1) The present invention proposes a beneficiation method for efficiently recovering barite from heat-treated drilling waste. Two different grades of barite powder products are obtained through magnetic separation and flotation, both of which can be used as raw materials for drilling weighting agents, thereby achieving efficient comprehensive utilization of this type of secondary resource and improving economic and environmental benefits.

[0026] (2) The composite collector composed of sodium oleate, benzohydroxamic acid and coconut amine used in the method of the present invention has good collecting, selectivity and foaming properties, and significantly reduces the entrainment of gangue minerals; coconut amine as an emulsifier improves the dispersibility and solubility of the collector, thereby enhancing the interaction between the collector and the target mineral;

[0027] (3) The composite inhibitor composed of sodium silicate and tannic acid used in the method of the present invention has a good selective inhibitory effect on gangue minerals such as quartz, hematite, and calcite, which is beneficial to improving the grade of barite products;

[0028] (4) The present invention uses conventional flotation equipment and reagents, and the process is simple and easy to implement in industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, they will be described in detail below with reference to specific embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0031] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0032] The process flow chart of the present invention is as follows Figure 1 The specific steps are shown in the embodiment.

[0033] Example 1

[0034] The drilling waste heat-treated in this embodiment has a BaSO 4 content of 69.60%, an Al 2 O 3 content of 2.45%, and a SiO 2 content of 13.46%.

[0035] Wet-screening the drilling waste with a sieve size of 38 μm to obtain an undersize product;

[0036] The undersize product is magnetically separated with a pulp concentration of 25% and a magnetic field strength of 3000 Gs to obtain magnetic and non-magnetic products.

[0037] The non-magnetic product was subjected to a roughing process. The pH adjuster used was dilute hydrochloric acid, and the pH of the pulp was adjusted to 8-9. The dispersant used was sodium carbonate, and the dosage was 400 g / t. The inhibitor used was composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage was 1000 g / t. The collector used was composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage was 900 g / t.

[0038] The rougher concentrate undergoes a primary cleaning process (cleaning process 1). The inhibitor used is sodium silicate and tannic acid in a mass ratio of 10:1, with a dosage of 600g / t. The collector is sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, with a dosage of 200g / t. The tailings from cleaning process 1 are returned to the rougher to form a closed circuit, and the cleaning process 1 concentrate is used as barite powder product 1.

[0039] The rougher tailings were subjected to three scavenging operations. The depressant used consisted of sodium silicate and tannic acid in a mass ratio of 10:1, at a dosage of 600 g / t. The collector used consisted of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, at a dosage of 200 g / t. The dosage of the reagents used in the three scavenging operations was the same.

[0040] The concentrates from scavengers 1 through 3 are combined and then subjected to two separate rounds of concentrating. The depressant used in Concentrate 2 is sodium silicate and tannic acid in a mass ratio of 10:1, at a rate of 400 g / t. The tailings from Concentrate 2 undergo a single scavenging (Scavenger 4) using a collector consisting of sodium oleate, benzohydroxamic acid, and cocamide MEA in a mass ratio of 160:20:1, at a rate of 150 g / t. The concentrate from Scavenger 4 is combined with the tailings from Concentrate 3 and returned to Concentrate 2 to form a closed circuit. Concentrate 3 undergoes blank flotation, with the concentrate used as barite powder product 2.

[0041] After testing, the BaSO4 content in barite powder product 1 is 95.30% and the density is 4.26g / cm 3 The yield is 37.62% and the recovery rate is 51.51%, which meets the China National Petroleum Corporation corporate standard Q / SY 17008-2019 drilling fluid weighting agent barite Grade I standard. The BaSO4 content in barite powder product 2 is 92.73% and the density is 4.15g / cm 3 The yield was 25.66%, the recovery rate was 34.19%, which met the barite grade II standard. The comprehensive recovery rate of barite was 85.70%.

[0042] Example 2

[0043] The drilling waste heat-treated in this embodiment has a BaSO 4 content of 68.14%, an Al 2 O 3 content of 3.52%, and a SiO 2 content of 15.88%.

[0044] Wet-screening the drilling waste with a sieve size of 74 μm to obtain an undersize product;

[0045] The under-screen product is magnetically separated with a pulp concentration of 25% and a magnetic field strength of 3000 Gs to obtain magnetic separation products and non-magnetic products;

[0046] The non-magnetic product was subjected to a roughing process. The pH adjuster used was dilute hydrochloric acid, and the pH of the pulp was adjusted to 8-9. The dispersant used was sodium carbonate, and the dosage was 400 g / t. The inhibitor used was composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage was 1500 g / t. The collector used was composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage was 1000 g / t.

[0047] The rougher concentrate undergoes a primary cleaning process (cleaning process 1). The inhibitor used is sodium silicate and tannic acid in a mass ratio of 10:1, with a dosage of 800g / t. The collector is sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, with a dosage of 250g / t. The tailings from cleaning process 1 are returned to the rougher process to form a closed circuit, and the cleaning process 1 concentrate is used as barite powder product 1.

[0048] The rougher tailings were subjected to three scavenging operations. The depressant used consisted of sodium silicate and tannic acid in a mass ratio of 10:1, at a dosage of 800 g / t. The collector used consisted of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, at a dosage of 250 g / t. The dosage of the reagents used in the three scavenging operations was the same.

[0049] The concentrates from scavengers 1 through 3 are combined and then subjected to two separate rounds of concentrating. The depressant used in Concentrate 2 consists of sodium silicate and tannic acid in a mass ratio of 10:1, at a rate of 500 g / t. The tailings from Concentrate 2 undergo a single scavenging (Scavenger 4) using a collector consisting of sodium oleate, benzohydroxamic acid, and cocoamine in a mass ratio of 160:20:1, at a rate of 200 g / t. The concentrate from Scavenger 4 is combined with the tailings from Concentrate 3 and returned to Concentrate 2 to form a closed circuit. Concentrate 3 undergoes blank flotation, and the concentrate is used as barite powder product 2.

[0050] After testing, the BaSO4 content in barite powder product 1 is 94.13% and the density is 4.21g / cm 3 The yield is 40.25% and the recovery rate is 55.60%, which meets the China National Petroleum Corporation corporate standard Q / SY 17008-2019 drilling fluid weighting agent barite Grade I standard. The BaSO4 content in barite powder product 2 is 90.87% and the density is 4.08g / cm 3 The yield was 24.82%, the recovery rate was 33.10%, which met the barite grade II standard. The comprehensive recovery rate of barite was 88.70%.

[0051] Comparative Example 1

[0052] Compared with Example 1, except that the collector was replaced by sodium oleate, the other steps and conditions were exactly the same as those in Example 1. That is, only sodium oleate was used as the collector, and the total amount remained unchanged.

[0053] After testing, the BaSO4 content of the obtained barite powder product 1 is 89.71%, and the density is 4.05g / cm 3 The yield is 48.95% and the recovery rate is 63.09%, which meets the China National Petroleum Corporation enterprise standard Q / SY 17008-2019 drilling fluid weighting agent barite grade II standard; the obtained barite powder product 2 has a BaSO4 content of 85.39% and a density of 3.98g / cm 3 The yield was 22.65% and the recovery rate was 27.79%, which did not meet the product standard of barite weighting agent for drilling fluid of China National Petroleum Corporation enterprise standard Q / SY 17008-2019.

[0054] Comparative Example 2

[0055] Compared with Example 1, except that the inhibitor was replaced by sodium silicate, the other steps and conditions were exactly the same as those in Example 1. That is, only sodium silicate was used as the inhibitor, and the total amount remained unchanged.

[0056] After testing, the BaSO4 content of the obtained barite powder product 1 is 91.03% and the density is 4.07g / cm 3 The yield is 39.59% and the recovery rate is 51.78%, which meets the China National Petroleum Corporation enterprise standard Q / SY 17008-2019 drilling fluid weighting agent barite grade II standard; the obtained barite powder product 2 has a BaSO4 content of 88.28% and a density of 4.03g / cm 3 The yield was 28.79% and the recovery rate was 36.52%, which did not meet the product standard of barite weighting agent for drilling fluid of China National Petroleum Corporation enterprise standard Q / SY 17008-2019.

Claims

1. A mineral processing method for efficiently recovering barite from heat-treated drilling waste, characterized in that: The following steps are involved: S1. Wet screening and classifying drilling waste to obtain undersize products and tailings; S2. The undersize product obtained in step S1 is subjected to magnetic separation to obtain a magnetic product and a non-magnetic product; S3. The non-magnetic product obtained in step S2 is subjected to a roughing process to obtain a roughing concentrate and roughing tailings; S4. The rougher concentrate obtained in step S3 is subjected to a concentration to obtain a barite powder product 1; S5. The rougher tailings obtained in step S3 are scavenged three times, and the three scavenged concentrates are combined and then subjected to two selections to obtain barite powder product 2; The reagent system for roughing in step S3 is as follows: the pH adjuster is dilute hydrochloric acid, which adjusts the pH of the slurry to 8-9; the dispersant is sodium carbonate, and the dosage is 300-600 g / t; the inhibitor is a combination of sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 600-1200 g / t; the collector is a combination of sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate:benzohydroxamic acid:coconut amine is (150-200):(15-30):1, and the dosage is 800-1000 g / t.

2. The ore dressing method for efficiently recovering barite from heat-treated drilling waste according to claim 1, wherein In step S1, the drilling waste components include barite, hematite, quartz, calcite, and lime.

3. The ore dressing method for efficiently recovering barite from heat-treated drilling waste according to claim 1, wherein In the wet sieving classification of step S1, the sieve aperture size is 38-74 μm.

4. The ore dressing method for efficiently recovering barite from heat-treated drilling waste according to claim 1, wherein In step S2, the magnetic separation frame concentration is 20%~30%, the magnetic field strength is 2000~4000Gs, and the obtained magnetic separation product is used as tailings.

5. The ore dressing method for efficiently recovering barite from heat-treated drilling waste according to claim 1, wherein The mass concentration of mineral solid particles in the flotation pulp of all flotation processes in steps S3 to S5 is 25% to 35%.

6. The ore dressing method for efficiently recovering barite from heat-treated drilling waste according to claim 1, wherein The selection in step S4 is selection 1, specifically, an inhibitor and a collector are added in sequence; the inhibitor is a combination of sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 400-800 g / t; the collector is a combination of sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate:benzohydroxamic acid:coconut amine is (150-200):(15-30):1, and the dosage is 200-300 g / t; the selected tailings are returned to the roughing step, and the selected concentrate is used as barite powder product 1.

7. The ore dressing method for efficiently recovering barite from heat-treated drilling waste according to claim 1, wherein Step S5 includes the following steps: The roughing tailings in step S3 are subjected to three scavenging operations, including scavenging one, scavenging two, and scavenging three. The dosage of the reagents used in the three scavenging operations is the same, specifically: the inhibitor is a combination of sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 500-800 g / t; the collector is a combination of sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate:benzohydroxamic acid:coconut amine is (150-200):(15-30):1, and the dosage is 200-400 g / t; the scavenging tailings obtained in the scavenging one are subjected to scavenging two, and the scavenging tailings obtained in the scavenging two are subjected to scavenging three, and the scavenging tailings obtained in the scavenging three are subjected to tailings treatment; The scavenged concentrates obtained from the three scavenging steps are combined for two concentrations, namely concentration 2 and concentration 3. Only inhibitors are used in the reagent system of concentration 2, while the inhibitor used in concentration 2 is a combination of sodium silicate and tannic acid, where the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 300-500g / t. Blank flotation is performed in concentration 3. The concentrate obtained from concentration 3 is used as barite powder product 2.

8. The ore dressing method for efficiently recovering barite from heat-treated drilling waste according to claim 7, wherein Step S5 also includes a scavenging, namely scavenging 4; scavenging 4 uses the tailings of the selection 2 as the flotation object, and only adds a collector. The collector used in scavenging 4 is a combination of sodium oleate, benzohydroxamic acid, and cocamide, wherein the mass ratio of sodium oleate:benzohydroxamic acid:cocamide is (150-200):(15-30):1, and the dosage is 100-200 g / t; the scavenged concentrate obtained in scavenging 4 is combined with the selected tailings obtained in selection 3 and then returned to selection 2; the scavenged tailings obtained in scavenging 4 are subjected to tailings treatment.

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