阅读说明：本技术 一种镍铁渣基磷酸镁水泥及其制备方法 (Ferronickel slag-based magnesium phosphate cement and preparation method thereof ) 是由 刘品 于 2019-11-21 设计创作，主要内容包括：本发明公开了一种镍铁渣基磷酸镁水泥,该镍铁渣基磷酸镁水泥以烧结氧化镁、镍铁渣混合物、磷酸盐、硼砂、缓凝剂作为原料制备,其中,镍铁渣混合物为酸化处理后的镍铁渣和氧化镁粉末的混合物,其处理过程为：将镍铁渣在真空环境中煅烧,随炉自然冷却至100~150℃后加入弱酸中,在弱酸中保温酸化处理后,加入氧化镁粉末混合均匀后于再次高温煅烧,并在煅烧后粉磨制成镍铁渣混合物；该镍铁渣基磷酸镁水泥在制备时将按顺序加入搅拌锅,经过搅拌后得到水泥胶凝材料,再依次进行浇筑、振捣和养护后成型。本发明能有效降低磷酸镁水泥的生产成本,并具有较佳的强度和稳定性。(The invention discloses a ferronickel slag-based magnesium phosphate cement which is prepared by taking sintered magnesium oxide, a ferronickel slag mixture, phosphate, borax and a retarder as raw materials, wherein the ferronickel slag mixture is a mixture of acidified ferronickel slag and magnesium oxide powder, and the treatment process comprises the steps of calcining ferronickel slag in a vacuum environment, naturally cooling to 100 ~ 150 ℃ along with a furnace, adding the mixture into weak acid, carrying out heat preservation and acidification treatment in the weak acid, adding magnesium oxide powder, uniformly mixing, carrying out high-temperature calcination again, and grinding after calcination to prepare the ferronickel slag mixture.)

1. The ferronickel slag-based magnesium phosphate cement is characterized by comprising the following raw materials in parts by mass:

60 ~ 80 parts of sintered magnesia

30 ~ 40 parts of ferronickel slag mixture

15 portions of phosphate 15 ~ 30 portions

10 portions and 10 ~ 15 portions of borax

Retarder 3 ~ 8 parts

The nickel-iron slag mixture is a mixture of acidified nickel-iron slag and magnesium oxide powder, and the treatment process comprises the steps of calcining the nickel-iron slag in a vacuum environment at 700 ~ 900 ℃ for 30 ~ 60min, naturally cooling the nickel-iron slag to 100 ~ 150 ℃ along with a furnace, adding the nickel-iron slag into weak acid, carrying out acidification treatment at the temperature of 60 ~ 70 ℃ for 50 ~ 90min, taking out the nickel-iron slag after 50 ~ min, adding magnesium oxide powder accounting for 6 ~ 8% of the mass of the nickel-iron slag, uniformly mixing the magnesium oxide powder, calcining the mixture at the temperature of 1000 ~ 1100 ℃ for 30 ~ 40min, and grinding the mixture to obtain the nickel-iron slag mixture.

2. The ferro-nickel slag-based magnesium phosphate cement according to claim 1, wherein the sintered magnesia is calcined and ground magnesite with a mass purity of more than 93%.

3. The ferronickel slag-based magnesium phosphate cement according to claim 1, wherein the sintered magnesium oxide and the ferronickel slag are subjected to two times of grinding treatment, the oversize of the ground magnesium oxide after 200-mesh sieving is less than 10%, and the specific surface area of the sintered magnesium oxide is more than 200m²/kg, and the specific surface area of the ferronickel slag is more than 220m²/kg。

4. The ferronickel slag-based magnesium phosphate cement according to claim 1, wherein the ferronickel slag is produced from electric furnace ferronickel slag as a raw material, and the measured mass percentage content of magnesium oxide in the electric furnace ferronickel slag is not less than 30%.

5. The ferro-nickel slag-based magnesium phosphate cement according to claim 1, characterized in that the phosphate is one or a mixture of monopotassium phosphate, ammonium dihydrogen phosphate and potassium dihydrogen phosphate, and the phosphate grade as a raw material is industrial pure with a mass purity of more than 96%.

6. The ferro-nickel slag-based magnesium phosphate cement according to claim 1, wherein the retarder is boric acid having a purity of 98% or more.

7. The ferro-nickel slag based magnesium phosphate cement according to claim 1, characterized in that the retarder is a mixture of boric acid, glucose, sucrose and citric acid, wherein the mass fraction of boric acid is not less than 50% and the sum of the mass fractions of glucose and sucrose is not more than 30%.

8. The ferro-nickel slag based magnesium phosphate cement according to claim 1, characterized in that the weak acid is a mixture acid of phosphoric acid, oxalic acid and formic acid in any proportion.

9. The ferronickel slag-based magnesium phosphate cement of claim 8, wherein the molar ratio of phosphoric acid, oxalic acid and formic acid in the mixture acid is 6:2: 1.

10. A preparation method of ferronickel slag-based magnesium phosphate cement is characterized in that the ferronickel slag-based magnesium phosphate cement is prepared from the raw material of any one of claim 1 ~ 8, and the production process comprises the following steps:

s1, weighing raw materials according to the calculated mixture ratio, sequentially and respectively putting sintered magnesium oxide, a ferronickel slag mixture, phosphate, borax and a retarder which are used as the raw materials into a stirring pot, firstly stirring at a low speed of 60 ~ 80rad/min for 30 ~ 60S to uniformly mix dry materials, then adding water, firstly stirring at a low speed of 60 ~ 80rad/min for 15 ~ 20S, and then stirring at a low speed of 300 ~ 900rad/min for 45 ~ 60S, so that cement mortar is fully and uniformly mixed to obtain a cement gelled material;

and S2, quickly pouring the uniformly stirred cement cementing material into a test mould, uniformly vibrating, then placing the test mould into the air for natural curing, removing the mould after curing for 2 ~ 3h, and naturally curing the test block in the air.

Technical Field

The invention relates to the technical field of cement preparation processes, in particular to ferronickel slag-based magnesium phosphate cement and a preparation method thereof.

Background

As one of three basic materials in the building industry, cement is the most used building material, has wide application and large using amount, is used as a powdery hydraulic inorganic cementing material, is usually mortar or concrete prepared by adding water and stirring, and is widely applied to construction engineering, traffic engineering, offshore platforms and other infrastructure engineering.

As a commonly used reinforced cement, Magnesium Phosphate Cement (MPC) is mainly prepared from sintered Magnesia, phosphate and retarder according to a certain proportion, and has the advantages of short setting time, quick development of early strength, high strength, good wear resistance, low shrinkage, high bonding strength of new and old concrete, good temperature-resistant property and the like. In the preparation process of magnesium phosphate cement, the influencing factors mainly comprise raw materials, magnesium-phosphorus ratio (M/P), water-cement ratio (W/B), retarder, admixture types, mixing amount and the like, wherein the content and quality of sintered magnesium oxide in the raw materials have a crucial influence on the performance of the magnesium phosphate cement, the sintered magnesium oxide commonly used in the field is mainly obtained by grinding magnesite after high-temperature calcination at more than 1600 ℃, the proportion of the sintered magnesium oxide in the magnesium phosphate cement can reach 50-80%, and the magnesium oxide obtained after calcination has high price, so that the price of the finished magnesium phosphate cement is high, and the application and popularization of the magnesium phosphate cement are not facilitated.

Besides magnesite, the nickel-iron slag is used as an industrial byproduct separated from the nickel-iron alloy, the emission amount is large, the actual recycling rate is low, most of the nickel-iron slag is stacked or buried in the open air, the ecological environment is threatened, the content of magnesium oxide in the nickel-iron slag is high, and the magnesium oxide is mainly forsterite (Mg)₂SiO₄) The mineral crystal phase form of (1) exists and can be utilized under an acidic condition, if the ferronickel slag can be applied to the preparation of magnesium phosphate cement through process improvement to proportionally replace sintered magnesium oxide in the raw materials, on one hand, the selection range of magnesium oxide raw materials in magnesium phosphate cement raw materials can be remarkably expanded, and the production cost is reduced; and on the other hand, the secondary recycling of industrial waste can be carried out, and the environmental burden is reduced.

Disclosure of Invention

The invention aims to provide the ferronickel slag-based magnesium phosphate cement and the preparation method thereof, the ferronickel slag-based magnesium phosphate cement utilizes industrial waste slag of ferronickel slag as a raw material to replace sintered magnesium oxide in the raw material, so that the cost is effectively reduced, and the technical defects in the prior art are overcome.

The technical problem solved by the invention is realized by adopting the following technical scheme:

the ferronickel slag-based magnesium phosphate cement comprises the following raw materials in parts by mass:

60 ~ 80 parts of sintered magnesia

30 ~ 40 parts of ferronickel slag mixture

15 portions of phosphate 15 ~ 30 portions

10 portions and 10 ~ 15 portions of borax

Retarder 3 ~ 8 parts

The nickel-iron slag mixture is a mixture of acidified nickel-iron slag and magnesium oxide powder, and the treatment process comprises the steps of calcining the nickel-iron slag in a vacuum environment at 700 ~ 900 ℃ for 30 ~ 60min, naturally cooling the nickel-iron slag to 100 ~ 150 ℃ along with a furnace, adding the nickel-iron slag into weak acid, carrying out acidification treatment at the temperature of 60 ~ 70 ℃ for 50 ~ 90min, taking out the nickel-iron slag after 50 ~ min, adding magnesium oxide powder accounting for 6 ~ 8% of the mass of the nickel-iron slag, uniformly mixing the magnesium oxide powder, calcining the mixture at the temperature of 1000 ~ 1100 ℃ for 30 ~ 40min, and grinding the mixture to obtain the nickel-iron slag mixture.

By way of further limitation, the sintered magnesia is formed by calcining magnesite with the mass purity of more than 93% and then grinding the calcined magnesite.

By further limitation, the sintered magnesia and the nickel-iron slag are subjected to two times of grinding treatment, the oversize allowance after being ground and passing through a 100-mesh sieve is less than 10 percent, and the specific surface area of the sintered magnesia is kept to be more than 200m²/kg, the specific surface area of the nickel-iron slag is more than 220m²/kg。

As a further limitation, the ferronickel slag preferably adopts electric furnace ferronickel slag obtained after electric furnace nickel preparation as a raw material, and the measured mass percentage content of magnesium oxide in the electric furnace ferronickel slag is not less than 30%.

As a further limitation, the phosphate is one or a mixture of monopotassium phosphate, ammonium dihydrogen phosphate and monopotassium phosphate, and the phosphate grade as a raw material is industrial pure and has the mass purity of more than 96%.

The retarder is boric acid with purity of more than 98%.

By way of further limitation, the retarder is a mixture of boric acid, glucose, sucrose and citric acid, wherein the mass fraction of boric acid is not less than 50%, and the sum of the mass fractions of glucose and sucrose is not more than 30%.

By way of further limitation, the weak acid is a mixture acid of phosphoric acid, oxalic acid and formic acid in any proportion, and the preferred molar ratio of phosphoric acid, oxalic acid and formic acid in the mixture acid is 6:2: 1.

A preparation method of ferronickel slag-based magnesium phosphate cement comprises the following main production processes:

s1, weighing raw materials according to the calculated mixture ratio, sequentially and respectively putting sintered magnesium oxide, a ferronickel slag mixture, phosphate, borax and a retarder which are used as the raw materials into a stirring pot, firstly stirring at a low speed of 60 ~ 80rad/min for 30 ~ 60S to uniformly mix dry materials, then adding water, firstly stirring at a low speed of 60 ~ 80rad/min for 15 ~ 20S, and then stirring at a low speed of 300 ~ 900rad/min for 45 ~ 60S, so that cement mortar is fully and uniformly mixed to obtain a cement gelled material;

and S2, quickly pouring the uniformly stirred cement cementing material into a test mould, uniformly vibrating, then placing the test mould into the air for natural curing, removing the mould after curing for 2 ~ 3h, and naturally curing the test block in the air.

Has the advantages that: the ferronickel slag-based magnesium phosphate cement has the advantages of similar performance to the traditional magnesium phosphate cement, high bonding strength, good volume stability and other excellent performances, better fluidity, higher early strength, controllable setting time, excellent physical and chemical properties after molding, capability of meeting the requirements of quick and strong construction, good application in the fields of quick repair and reinforcement of concrete structures and the like, and wide application prospect in the aspects of solidification treatment of hazardous wastes and the like.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.