Refractory Mortar

Durable and Reliable Solution for High-Temperature Bonding and Sealing

Refractory Mortar is a reliable and durable material for bonding and sealing in high-temperature conditions. With its excellent thermal resistance, mechanical strength, and chemical resilience, it is indispensable in many industrial applications. Modern production technologies ensure the high quality of the product, meeting international standards. As a global supplier, we provide materials that help enterprises achieve high efficiency and reliability in their production processes.

Types of Mortar

Refractory mortar is an essential component in the installation and repair of refractory structures, ensuring a strong bond between materials and masonry elements capable of withstanding high temperatures and aggressive environments. This specialized material, composed of refractory components, guarantees durability and reliability in high-temperature processes across key industries such as metallurgy, cement, coke-chemical, and others.

Mol_10

Mol_11

Mol_12

Mol_5

Mol_9

Mol_1

Mol_7

Mol_4

КОР_Mol_8

КОР_Mol_6

Mol_3

Technical Description

Mortars are classified based on their primary filler into fireclay, silica, thermal insulation, and other types. All of them must meet certain general requirements depending on their intended use. To ensure a dense joint that firmly bonds masonry elements, the mortar’s chemical composition should closely match that of the bonded products and should not cause excessive shrinkage.

Erbau Industrial Group offers for delivery different types of mortars, which according to DIN 1089 corresponds to the following quality indicators:

Table 1. SILICA refractory mortar

Properties				Grades		Tests in accordance with
				KS 94	KS 91
				Typical application
				Coke oven battery partitions with high operating temperature	Coke oven battery partitions, oven chamber vault, regenerator walls and medium structures
Chemical composition	SiO₂	%	Х	≥ 94	≥ 91	DIN 51 070 Part 2
	Al₂O₃ + TiO₂	%	Х	≤ 5,5	≤ 7,5	DIN 51 070 Part 3, 4
	Sum of foreign oxide	%	Х	≤ 1,5	≤ 2	DIN 51 070 Part 5,7,8
Grain size distribution	< 0,063mm	%		Must be agreed on the basis of delivery date by the manufacturer.		Section 3.4.1
	from 0,063 to 0,125mm	%
	from 0,125 to 0,25mm	%
	from 0,25 to 0,5mm	%
	from 0,5 to 1,0mm	%
	from 1,0 to 2,0mm	%	Х	≤ 2
	> 2,0mm	%	Х	0
Consistency	Required mixing water, on a dry material basis	ml/100gr	Х	≤ 35		Section 3.5
Consistency	Penetration depth	mm	Х	Must be agreed on the basis of delivery date by the manufacturer.		Section 3.5
Constant line, changing due to drying	Drying shrinkage	%	Х	≥ -4	≥ -5	Section 3.6.1
Curing (cold bending strength)	Cold bending strength after drying at 110°C	N/mm²	Х	≥ 0,1		Section 3.6.2
Curing (cold bending strength)	Cold bending strength after drying at 1100°C	N/mm²	Х	≥ 0,7		Section 3.6.2
Compression cracking (DFL)	Δ D25	%	Х	≥ -0,7		Section 3.6.3 and DIN 51 053 Part 2

Table 2. FIRECLAY refractory mortar

Properties				Grades		Tests in accordance with
				KC – W	KC – D
				Typical application
				Regenerator walls and regenerator of pass walls	Oven chamber vault, risers, doors and under regenerators
Chemical composition	SiO₂	%	Х	≥ 94	≥ 91	DIN 51 070 Part 2,3
Chemical composition	Al₂O₃ + TiO₂	%	Х	≤ 5,5	≤ 7,5	DIN 51 070 Part 2,3
Grain size distribution	< 0,063mm	%		Must be agreed on the basis of delivery date by the manufacturer.		Section 3.4.1
	from 0,063 to 0,125mm	%
	from 0,125 to 0,25mm	%
	from 0,25 to 0,5mm	%
	from 0,5 to 1,0mm	%
	from 1,0 to 2,0mm	%	Х	≤ 2
	> 2,0mm	%	Х	0
Consistency	Required mixing water, on a dry material basis	ml/100gr	Х	≤ 40		Section 3.5
Consistency	Penetration depth	mm	Х	Must be agreed on the basis of delivery date by the manufacturer.		Section 3.5
Constant line, changing due to drying	Drying shrinkage	%	Х	≥ -5	≥ -6	Section 3.6.1
Curing (cold bending strength)	Cold bending strength after drying at 110°C	N/mm²	Х	≥ 0,1	–	Section 3.6.2
Curing (cold bending strength)	Cold bending strength after drying at 1100°C	N/mm²	Х	≥ 0,7	–	Section 3.6.2
Compression cracking (DFL)	Δ D25	%	Х	≥ -0,1		Section 3.6.3 and DIN 51 053 Part 2
Compression cracking (DFL)	Δ D25	%	Х	≥ -0,3		Section 3.6.3 and DIN 51 053 Part 2

To receive the best service and quality

How the Production Process Works

The production of Refractory Mortar involves several key stages, each aimed at ensuring the high thermal resistance, adhesion, and chemical stability of the final material. The main stages of production include: raw material preparation, grinding the raw materials to the required grain sizes, dosing the raw materials and all necessary additives, thorough mixing, packaging of the finished powder, and sealing it in moisture-resistant bags.

As the primary filler, refractory clay and binding materials are used, ensuring the key properties of mortars—refractoriness, strength, and chemical resistance.

Рlasticity and workability of the mortar are adjusted by adding plasticizing additives. Mortars acquire plastic properties with a lower water content, allowing for the formation of a strong joint with a significantly reduced seam thickness, as well as lower porosity and shrinkage.

The grain composition of the powder depends on the minimum allowable thickness of the masonry joint. The largest grains in the powder should be 2-3 times smaller than the joint thickness.

Mixing

Components are mixed in special mixers to create a homogeneous mass. For dry mortars, the components are mixed in their dry form, while for ready-to-use pasty mortars, water or other liquid binders are added until the desired consistency is achieved.

Processing and Quality Control

Prepared mixture undergoes testing based on the following parameters:

Chemical composition;
Mass loss during firing;
Refractoriness;
Moisture content;
Grain composition.

Plasticity and adhesion

The material’s ability to bond with refractory surfaces is assessed. A high-quality mortar should be both stable and flexible. When pressure is applied with a refractory product, the mortar should fill all uneven surfaces of the masonry while still allowing the product to move easily during installation. Additionally, the mortar should not dry prematurely, maintaining its plasticity and preventing separation before being applied to the refractory products.

Packaging and Storage

Finished mortar is packaged into Bags (for dry mixtures), Containers or Buckets (for ready-to-use pasty mortars). Mixture is stored in dry conditions to prevent moisture absorption (for dry mortars) or freezing (for liquid compositions).

Use in Production

Before use, the mortar may require additional mixing with water or liquid additives according to the manufacturer’s recommendations.

Historical Background of Refractory Mortars

The history of refractory mortars is closely tied to the development of refractory materials in general. Initially, natural refractory clays were used, which had the ability to withstand high temperatures. However, over time, specialized mortar compositions were developed for various types of industrial furnaces.

First references to the use of refractory materials for bonding stones or bricks date back to the times of Ancient Egypt and Mesopotamia. In those days, mixtures based on natural clays were used to construct furnaces and fire-resistant structures capable of withstanding high temperatures during ceramic firing or metal smelting. These mortars were often mixed with sand or other natural materials to improve their heat-resistant properties.

With the development of metallurgy in the 18th and 19th centuries, when furnaces were used for metal smelting at very high temperatures, there arose a need for stronger and more effective refractory mortars. During this period, mixtures including chamotte, clay, and other specialized materials were developed, allowing them to withstand temperatures up to 1600-1700°C.

By the mid-20th century, the technology for manufacturing refractory mortars was improved, and new specialized compositions emerged, capable of working in more aggressive environments such as blast furnaces, cement plants, and other high-temperature installations. Refractory mortar became a crucial component in the construction and repair of high-temperature industrial furnaces, where it was necessary to ensure the sealing and strength of structures under constant temperature fluctuations.