SK157395A3 - Mineral wool and method of manufacture - Google Patents

Abstract

The production and physiological dissolution rate of mineral wool formed of MMV fibres containing 35-66 % SiO2, up to 10 % Al2O3, 10-45 % CaO, 2-30 % MgO, up to 10 % FeO, 0-7 % Na2O + K2O and 0-10 % TiO2 is improved by including both P2O5 and B2O3 in the composition.

Description

The mineral wool contains 35 to 66 wt. % silica, up to 10 wt.% alumina, 10 to 45 wt. % calcium oxide, 2 to 30 wt. % magnesium oxide, up to 10 wt. % ferrous oxide, up to 7 wt. % sodium oxide and potassium oxide, up to 10 wt. % of titanium dioxide, up to 20 wt. phosphorus pentoxide and boron oxide; and other elements. Also disclosed is a method for producing mineral wool.

and

Glass wool of chemically produced fibers

Technical field

The present invention relates to man-made vitreous fiber MMVF which contains iron and a relatively high amount of alkaline earth metals. and a low amount of alkali metals, commonly known as mineral, slag or basalt wool.

BACKGROUND OF THE INVENTION

Various types of MMV fibers are known.

It is known that in the processing of traditional glass fibers, components that provide boron oxide (borate) are preferably added to the glass melt. This will improve the properties of glass and glass melt. However, borate-containing feedstocks are expensive and are normally not added at all when possible, especially if the product contains iron and has a low alkali and alkaline earth metal content, as is the case with conventional mineral and slag melts.

Fiberglass products usually have a relatively high alkali metal content (often more than 13% Na ₂ O + K ₂ O). In this specification, all analyzes are expressed as mass of the total composition, which is measured as oxides. Glass fibers and> glass wool usually do not contain iron, but often contain boron.

They usually contain less than 7% Al ₂ O ₃ . Nevertheless, E-glass is designed for fibers or other non-wadding products and may have a high aluminum content and a low or zero alkali content. For example, JP-A-50090719 discloses E-glass, which contains 15 to 16% A10, 9.5 to 10.5% B ₂ 0 ₃ and 5% P ₂ O _s. Free of iron and sodium.

EP-A-9418 describes glass fibers which can be widely used in optics and contain iron, boron and phosphorus. None of the above compositions contain both boron and phosphorus at the same time and all contain more than 13% alkali metal oxides.

WO93 / 07741 describes fibers containing 0 to 4% P ₂ 0 _s, of more than 13% _of O, and up to 8% A1 ₂ O _3, which are used in horticulture. B ₂ 0 ₃ may also be present, but the total amount of impurities (among which B ₂ 0 ₃ belongs) shall not exceed 1%.

The glass wool described in EP-A-412878 has a high alkali metal content (more than 13%) and contains borate. Iron-free. Phosphorus is an optional component. Reportedly added to improve fiber solubility.

We were interested in improving the solubility in such waves, which are commonly referred to as mineral, slag or basalt, and usually contain iron, low aluminum (less than 10%), low alkali (less than 7%) and noticeable metals alkaline earth (more to about 12%).

It would be desirable to provide such waves whose MMV fibers are soluble in a physiological medium, particularly in a pulmonary fluid.

It is known that the composition of the fibers can appreciably affect their solubility. For example, in WO87 / 05007 it is illustrated that fibers having a low aluminum content, particularly those having a content of less than 10% by weight of the composition, have improved solubility in the physiological environment. It is also known that the incorporation of phosphorus can improve solubility in physiological medium. This is exemplified by the mineral wool fibers of the invention. These are mineral wool fibers which contain 1 to in the form of ^p 2 ° _s. This component reportedly improves solubility in physiological medium. Thus, it can be said that increasing the amount of phosphorus in this range leads to an increase in solubility.

during the processing of MMVF wool, the fiber constituents are melted in the furnace, such as an electric furnace, a shaft, a melting tub, or a cupola. This produces a melt which can be spun. The melt typically has a melting point of 1400 to 1600 ° C, so the furnace is heated above this temperature. It has been found that incorporating a noticeable amount of phosphorus into the melt may lead to some problems. For example, phosphorus can evaporate in the furnace, leading to difficulties in controlling the composition. In particular, an increase in phosphorus can adversely affect viscosity and overall properties. There is an increased risk of melting (if there is a high iron content and little or no alkali metal content

EP-A-459.897. 10% phosphorus and low aluminum) during the separation and crystallization phases. This leads to the formation and accumulation of solid or slag material in or on the device used to form the melt and convert the melt into fibers, causing an increase in the amount of grain formation during fiber formation, reducing material efficiency and leading to higher cost.

Therefore, it is desirable to provide MMVF cotton whose dissolution characteristics are as expected for those having a high phosphorus content, but there are no processing problems associated with a relatively high phosphorus content.

These problems are exacerbated as the phosphate content of the melt increases. For example, problems occur when the phosphate content rises above 5%. In some furnaces it is possible to use up to 10% phosphate, but it is generally not appropriate to use a higher content for processing purposes.

However, even at low contents, and especially if it is not possible to produce a melt containing very small amounts of aluminum, the dissolution rates of the fibers are not as high as would be desirable with these amounts of phosphate.

Therefore, it is desirable to improve the solubility of MMV fibers in physiological medium without the need to increase the phosphate content, which leads to processing problems.

Fibers containing phosphorus and boron are described in WO94 / 23801, from which the present invention claims priority.

SUMMARY OF THE INVENTION

The present invention describes MMVF wadding, which is made up of fibers formed by the composition it contains, by weight of oxides (with iron expressed as FeO):

You are about

Al 0

3

CaO

MgO

FeO

Na 0 + K 0 2 2

Tio

P ₂ 0 _s + B-, 0 ₃ and other elements that include both P ₂ 0 _s and B ₂ 0 _e to 66% to 10% to 45% to 30% to 10%

Up to 7% to 10% to 20% by weight

We have surprisingly found that by using a melt containing borate and phosphate, fibers with suitable physiological solubility can be obtained from a melt that is well processed and has good viscosity and temperature characteristics, especially when the Al ₂ O ₃ content is low.

We have found that an upper limit of 10% phosphate will help to reduce processing problems, especially during the separation phase. The content is preferably 6% or less and is usually less than 5%. We have found that the inclusion of borate will increase the solubility of the fibers in a physiological environment without the need to use high amounts of phosphate and allow the use of phosphate in an amount of less than 5% while maintaining adequate physiological solubility. We have also found that borate has the additional advantage of the physical properties of the melt, especially melting, so that the risk of phase separation is reduced.

We have also found that the use of boron in phosphorous-containing fibers leads to improved fiber properties. For example, tensile strength, modulus of elasticity and length to diameter ratio are improved. The tensile strength is> 700 MPa. The modulus of elasticity is <150 GPa. The length to diameter ratio is> 700, especially if the fibers were produced in a cascade spinning machine.

The melt viscosity of the composition at 1400 ° C is preferably 10 so that it improves helps to lower the temperature of up to 70 poise and more preferably 15 to 30 poise.

The fibers preferably have a dissolution rate of at least 30 nm / day, preferably at least 50 or at least 60 nm / day at pH 7.5, as measured by the steady-state method described in Environmental Health Perspectives, 102, Appendix 5, October

1994, pages 83-86.

The cotton of the present invention can be produced by any known method. The present invention also provides a method for producing MMVF wadding consisting of fibers having the composition set forth above, the method comprising preparing the raw materials for the composition, preparing the furnace, placing the raw materials in the furnace and heating them to a temperature of 1400 to 1600 ° C, to form a melt, melt spinning, and wool-like fibers.

In this method we have utilized all the processing advantages mentioned above. Preferably, the cotton of the present invention is produced by the method of the present invention.

In the process of the present invention, the raw materials used to produce the melt are any known raw materials used to form the composition. Raw materials that can be used include, for example, diabase, cement, clay, olivine sand, quartz sand, waste foundry sand, rasorite, aroundanite, and other materials containing boron, treatment slag, blast furnace slag, electric arc furnace slag, iron oxides , waste mineral wool, asbestos waste, lime, sodium carbonate, waste glass, dolomite mass, bauxite, ferrous silicate, calcium phosphate, quartz sand and other known fusible components.

Preferably, the meltable composition and therefore the fiber-forming composition is comprised of at least 45%, often at least 47 or 48% SiO _2. The amount is usually less than 64 or 65%, preferably less than 60%. Often the amount of SiO _{2 is} 53.5 to 64%.

The composition preferably has a low aluminum content, generally in an amount of generally maintained as 3 or 2%.

less than 6% and preferably less than 4%. In general, it is very expensive to obtain raw materials which contain no aluminum at all, so that Al _and O ₃ are present in a certain amount, at least 0.5%, although the amount of aluminum is as low as possible, preferably less. often appropriate

The compositions usually contain at least 5%, generally at least 10% and even more preferably 15% alkaline earth metal oxides (CaO and MgO). Generally, these amounts are not more than 50%. The CaO is preferably present in an amount of 10 to 35%. In some compositions an amount of 10 to 20% is preferred, but in others an amount of 15 to 30% is preferred. The MgO is usually present in an amount of at least 1%, often 5 to 20%, preferably 7 to 20%. For example, it may be in the range of 5 to 15%.

The composition contains iron and is up to 10% by weight of the total composition, measured as FeO. Preferably, the iron is present in an amount of at least 0.5 to 1%. An amount of up to 4% is often appropriate, but the amount may be up to 9 or 10%, e.g. in the range of 6.5 to 9%.

The composition may contain alkali metals (Na ₂ O and K ₂ O) in an amount of 0% to 6 or 7%. Generally, Na ₂ O is present in an amount of 0% to 4% and K ₂ O is present in an amount of up to 2%. Usually each is present in an amount of at least 0.1%, but both are optional and may be omitted.

The phosphate is generally present in the composition in an amount of 0.5 to 0.5

10 i measured as often in the range of 3 to 6%. For processing purposes, it is desirable that the amount of phosphate be as low as possible while maintaining a sufficient amount to maintain the desired dissolution effect. Preferably, the amount of phosphate is at least 0.5, but less than 5% (e.g., up to 4.5%), even more preferably less than 4%. Usually it is at least 2 or 3%.

Borate is included in an amount of up to 10%, measured as B ₂ 0 ₃ . The amount is preferably greater than 0.5 or 1%.

In general, they should be added in a sufficient amount to increase the dissolution rate in a physiological environment, but the use of large amounts of borate makes it necessary to use a very expensive raw material. An amount of borate below 5% (eg 4,5% and

Ί less) can give good results in terms of prices, but sometimes quantities of 7 or 8% are preferred. The amount must be sufficient to achieve a useful effect and so is normally greater than 0.5 or 1% and, preferably, is at least 3%. The amount of B ₂ 0 ₃ is usually lower than the amount of P ₂ O _s for economic reasons.

TiO ₂ is optional. If present, the amount is usually 0.1 to 2%. The molten preparation may additionally contain 0 to 20% of other components, for example BaO, ZnO, ZrO ₂ , F, MnO, Li ₂ O, SrO. The total amount of the other ingredients is usually not more than 5% or at most 10%.

Preferably, the melt and the fibers consist of:

SiO ₂ 45 to 46%, preferably 46 to 70 or 48 to 60%

Al O 0.5 to 4%

CaO 10 to 35%

MgO 5 to 20%, preferably 5 to 15 or 7 to 15%

FeO 1 to 10%, preferably 1 to 9%

At 0 to 4%

K 0 to 2%

TiO ₂ 0 to 2%

P ₂ O _with at least 0.5% but preferably less than 5%

B ₂ O _{3 of} at least 0.5%, but preferably less than 5%, of an additional component of up to 5%.

all percentages are by weight of the total composition, and iron oxides are measured as Feo.

The raw materials are placed in an oven where they are heated to a temperature of 1400 to 1600 ° C to form a melt. Generally, the feedstocks are heated to at least 1450 ° C, preferably to a temperature of 1450 to 1540 ° C, generally to 1480 to 1520 ° C.

The furnaces that are used in the present invention to form a melt that is spun include the cupola, oil and / or gas-fired shaft furnaces or melting tub furnaces or electric furnaces. In these furnaces, the realization of the invention is most advantageous, although the composition also exhibits the stated advantages also when using known types of furnaces. Preferred furnaces are those into which air is blown. Slag formation and any evaporation problems are minimized by the process of the present invention.

The melt is spun by any known method. In particular, it can be spun by pouring into a rapidly rotating container, which is placed in a horizontal position and has perforated side walls through which the fibers are extruded or poured into one or more throwing wheels. Each wheel is placed on a separate horizontal axis. The melt poured on the circumference of the casting wheel ejects in the form of fibers. Although one wheel can be used, a cascade system is preferably used in which the melt is poured onto the upper rotor of the rotating rotor assembly, each of which is positioned on a different horizontal axis and set so that the melt flows from the upper rotor to the next rotor or for each successive rotor in the sequence such that the mineral fibers from each rotor are collected in a collection chamber. Any known apparatus used for spinning mineral melts can be used to form the mineral melt fibers, but particularly the apparatus described in our patent publication WO92 / 06047 is preferred.

The fibers may be stored as fabric or felt. The fabric may be overlapped to form a felt. The felt can be solidified in any known manner to the desired MMVF wadding product.

Binders are usually used in the felt. For example, it may be sprayed into the fibers before it is collected as a fabric or felt.

The wadding may be in the form of a shaped felt or other elements, or it may be in the form of tufts or granules of mineral wool fibers or in the form of particles made of such tufts or granules.

MMVF wadding can be used for any use for which MMVF wadding is used, for example in horticulture as a growth medium, for sound or thermal insulation and protection, for fire protection and as a filler or reinforcement.

DETAILED DESCRIPTION OF THE INVENTION

The following are examples of suitable formulations (determined by X-ray fluorescence analysis and measured as weight%) and their dissolution rate at pH 7.5 in nm per day. Each composition may be melted in cupola and spun by the process described in WO92 / 06047.

Compositions 1, 2, 3 and 4 fall within the scope of the present invention, while ΙΑ, 1B, 2A, 3A and 4A are for comparison and show that omission of boron will reduce dissolution rate. Boron-free comparatives tend to form a slag, especially at higher phosphorus content.

resources

You are about

A1 _A

TiO

FeO

CaO

MgO

At 0 2 ^P 2 ° dissolution rate | at pH

7.5 1 53.4 3.6 0.5 2.5 16.9 10.1 3 0.5 5.1 3.2 65.5 IA 56.4 3.5 0.5 1.8 19.7 10.7 4.3 0.5 0 2.8 40.3 1B 54.6 4.3 0.6 2.8 15.6 10.6 4.7 0.6 0 1.3 8.6 2 58.1 3.3 0.5 2.1 18.9 10.3 3.4 0.5 3.2 2.5 53.9 2A 56.4 3.5 0.5 1.8 19.7 10.7 4.3 0.5 0 2.8 40.3 3 47.8 1 0.1 1.1 33.2 8.3 0.1 0.1 2.2 4 | 54.8 3A 46.9 2.4 0.4 1.3 32 9.2 0.1 0.5 0 6 | 23.8 4 54.2 2.4 0.1 3.9 21.2 8.2 0.1 0.3 5.9 2.2 57.9 4A 53.2 3.2 0.1 7.3 23.4 5.3 0.1 0.3 0 3.6 | 16.7

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Industrial usability

The compositions of the present invention can be used to produce glass wool that is better manufactured and dissolves more quickly in a physiological environment.

Claims (8)

1. Mineral wool consisting of MMV fibers, characterized in that it has a composition expressed in total composition, characterized by the mass of oxides of You are about Al O 2 CaO MgO FeO Na O + K O 2 2 TiO P ₂ O _s + B_, O ₃ and other elements that include both P 0 and BO. ^J 2 5 2 5 35 to 66% up to 10% 10 to 45% 2 to 30% up to 10% Up to 7% Wool according to claim 1, characterized in that the content of Al O is up to 4% and the content of PO and B O is 0 to 10% by weight. 2 3 5 2 2 ^J 3 ^J in CA was 10%. by Wool according to claim 1 or claim 2, characterized by: c is 30%, Mg content < wherein the content of SiO is 53.5 to 65%, the content of CaO is 10 to 65% 0 is 5 up to 20% and the FeO content is up to 9%. 4. Wool by Claim 1, characterized by that the composition comprises You are about 2 53.5 to 64% by weight A1 ₂ O ₃ up to 4% by weight CaO 10 to 20% by weight MgO 10 to 20% by weight FeO 6.5 to 9% by weight PO + B 2 5 ABOUT 2 3 up to 20% by weight and each up to 10% 5. Wool by Claim 1, characterized by that the composition comprises You are about 2 53.5 to 65% by weight Al 0 2 3 up to 4% by weight CaO 15 to 30% by weight MgO 5 to 15% by weight FeO P by up to 4% by weight to 20% by weight, each up to 10%. by The wool of claim 1, wherein the composition comprises P ₂ O 1, denote a B 0 a 2 3 You are about 2 45 to 60% by weight αι ₂ 0 ₃ 0.5 to 4% by weight CaO 10 to 35% by weight MgO 5 to 15% by weight FeO 1 to 10% by weight At 0 2 0 to 4% by weight K 0 2 0 to 2% by weight TiO 2 0 to 2% by weight next ingredients 0 to 5% by weight. 7. Wool according to any one of the claims; čuj ú c a is characterized in that it comprises ^P ₂ O ⁱⁿ to 6, in an amount of 1 B ₂ O ₃ in an amount of 1 to 10%, preferably 1 to 5%. from n to up to 5% a Wool according to any one of claims 1 to 7, characterized in that it contains P ₂ 0 _s in an amount of 0.5 to 4.5% and / or B ₂ O ₃ in an amount of 0.5 to 4.5%. Wool according to any one of claims 1 to 8, characterized in that its velocity at pH 7.5 is at least 30 nm / day. A method for producing MMVF wadding as claimed in any one of claims 1 to 9, characterized in that it comprises preparing raw materials for the composition, preparing the furnace, placing the raw materials in the furnace at a temperature of 1400 to 1600 ° C to form a melt. , melt spinning and fiber removal in the form of cotton wool. 11. The method of claim 1, wherein the furnace is a cup of claim 9