Monolithic Refractories: Manufacture, Properties, and Selection

API TECHNICAL REPORT 978 FIRST EDITION, MARCH 2019

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Foreword

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  iii

  
  

  1. Scope 1

  2. Referenced Documents 1

  3. Terms and Definitions 2

  4. Background 9

     1. Early Beginnings 9

     2. Formulation Differences 9

     3. Cement Bonded Refractories 10

     4. Comparison with Other Refractories 11

     5. Other Types of Refractories 12

     6. Non-refractory Applications of Calcium Aluminate Cement [1, 7, 8, 9, 10] 13

  5. Constituent Ingredients of Refractory Concretes 14

     1. Introduction 14

     2. Binders 14

     3. Aggregates 15

     4. Water 19

  6. Constituent Ingredients of Plastics 21

     1. Introduction 21

     2. Particle Size/Moisture Level 21

     3. Aggregates 22

     4. Fine Grained Additives 23

     5. Binder Ingredients 23

     6. Manufacturing Methods 25

  7. Selection Criteria for Refractory Concrete 26

     1. Introduction 26

     2. Castables and Field Mixes 26

     3. Service Temperature Range 34

     4. Thermal Cycling 34

     5. Load Bearing Considerations 35

     6. Manufacturing Methods 35

     7. Corrosion Influences 35

     8. Binder Types 36

     9. Aggregate Types 37

     10. Abrasion and Erosion Resistance 37

     11. Methods of Installation 37

     12. Application and Use 38

     13. Faster Dryout 38

  8. Selection Criteria for Plastic Refractories 39

     1. Introduction 39

     2. Defining the Service Requirements 41

     3. Choice Between Pre-fired Brick and Monolithic Refractories 42

     4. Choice Between Plastics and Refractory Concretes 42

     5. Performance and End-use Requirements 46

     6. Recommended Selection Procedure 51

  9. Composition and Proportioning 52

     1. Introduction 52

        v

        
        

     2. Basis for Proportioning 52

     3. Field Mixes 53

     4. Water Content 54

  10. Plastics Characteristics 54

      1. Introduction 54

      2. Selection of a Plastic Refractory 55

      3. Classification 56

      4. Chemical Analysis 56

      5. Sampling 57

      6. Product Characteristics 57

  11. Engineering Properties and Testing 61

      1. Permanent Linear Change (ASTM C179) 62

      2. Thermal Expansion 62

      3. Mechanical Strength and Structural Stability 63

      4. Cold Compressive Strength (Crushing) 64

      5. Cold Modulus of Rupture 64

      6. Hot Strength (ASTM C583) 65

      7. Hot Modulus of Rupture 65

      8. Thermal Structural Stability (ASTM C832 and ASTM C16) 65

      9. Modulus of Elasticity and Stress-strain Properties (ASTM C885 and ASTM C1419) 65

      10. Permeability (ASTM C577) 66

      11. Thermal Properties 66

      12. Thermal Shock and Spall Resistance 68

      13. Electrical Resistivity 68

      14. Abrasion/Erosion Resistance (ASTM C704) 68

      15. Resistance to Carbon Monoxide (ASTM C288) 69

      16. Resistance to Slag Attack 69

      17. Status of Testing Procedures 70

  Bibliography 71

  
  

  Figures

  1. Typical Taylor Screen Analysis of Plastics and Ramming Mixes 21

  2. Typical Production Flow Sheet for the Manufacturer of Plastic Refractories 26

  3. Temperature Drop versus Thickness for Different Refractory Castables [Hot-face Temperature Contact at 2000 °F (1090 °C)] 36

  4. Refractories in a Petroleum Coke Calciner Showing the Use of Plastics, Castables

     and Ramming Mixes 40

  5. Determining the Consistency of Freshly Mixed Refractory Castable Using the ASTM C860

     Ball-in-hand Test 54

  6. Net Thermal Expansion of a Typical Super-duty Plastic Recovery 63

  7. Effect of Temperature on the Modulus of Rupture and Cold Crushing Strength of an 85 % Alumina Phos-bonded Plastic Refractory 64

  8. Thermal Conductivity of Various Plastic Refractories 67

  
  

  Tables

  1. Characteristics of Calcium Aluminate Cement Binders 15

  2. Maximum Service Temperatures of Selected Aggregates Mixed With Calcium Aluminate

     Cements under Optimum Conditions 15

  3. Aggregate Grading 17

  4. Types of Lightweight Aggregates Used in Refractory Insulating Concretes 18

  5. Effect on Calcium Aluminate Cement of Various Additives and Admixtures 20

  6. Acid-neutral Aggregates 22

  7. Liquid Binder Ingredients for Plastics 24

  8. Dry Binder Ingredients for Plastics 25

  9. Characteristics of Normal Weight Refractory Concretes 28

  10. Characteristics of Lightweight Refractory Concretes 33

  11. Methods of Installing Monolithic Refractories 43

  12. Properties of Chemically Similar Monolithic Refractories (All Based on Tabular Alumina

      Aggregates) 44

  13. Product and Performance Factors Considered in the Selection of Calcined Clay-based Plastics

      for Refractory Applications 47

  14. Strength, Volume, Stability, and Installed Density of Phosphate-bonded and Conventional High-alumina (50 % to 90 % Al2O3) Plastics and Conventional Calcined Clay-based Plastics

      (40 % to 47 % Al2O3) 48

  15. Product and Performance Factors Considered in the Selection of High-alumina Plastics and . . . . . . . Ramming Mixes for Refractory Applications 48

  16. Product and Performance Factors Considered in the Selection of Graphitic/Carbonaceous

      Plastics and Ramming Mixes 49

  17. Product and Performance Factors Considered in the Selection of Magnesia-based Ramming

      Mixes and Refractory Applications 50

  18. Product and Performance Factors Considered in the Selection of Zircon-Based Ramming Mixes

      for Refractory Applications 50

  19. Product and Performance Factors Considered In the Selection of Chrome Ore-Based Plastics/ . . . . . Ramming Mixes for Refractory Applications 51

  20. Classification of Fireclay and High-alumina Plastic Refractories and Ramming Mixes

      (ASTM C673) 57

  21. Properties of Plastics and Ramming Mixes 58

  
  

  Introduction

  
  

  API TR 978 is the first in a series of three API technical reports updating the state-of-the-art use of refractory concrete (castables), plastics, and ramming mixes in applications for the Hydrocarbon Processing Industry (HPI). This technical report is complemented by two additional reports in this series:

  
  

• API TR 979, Applications of Refractory Lining Materials

  
  

• API TR 980, Monolithic Refractories: Installation and Dryout

These three API technical reports are based on two original reports written by the American Concrete Institute (ACI) Committee 547 and published by ACI in 1979 and 1989. The original ACI reports are ACI 547.R-79, State-of-the Art Report: Refractory Concrete and ACI 547.1R-89, State-of-the Art Report: Refractory Plastics and Ramming Mixes. ACI granted API a license to use all material from the two original ACI reports, in need of revision at the time, for the betterment of the oil and gas industry.

ACI Committee 547 was organized in 1969 to provide a reliable and comprehensive source of information on monolithic refractories technology. In subsequent years, ACI support from the refractory technical community waned and shifted in favor API. API has an Individual Certification Program (ICP) for refractory practitioners based on the API Standard 936, Refractory Installation Quality Control-Inspection and Testing Monolithic Refractory Linings and Materials. To facilitate development of updated content in API’s certification program, ACI has allowed API to use the material from the two ACI reports, mentioned above, as the starting point for three new API technical reports, which and add to and revise the content of the two ACI reports.

The American Petroleum Institute formed the Vessel Refractory Task Group in the late 1980s with the objective of providing a standard for inspection and application quality control of monolithic refractories used in refining applications. In response to demands for greater reliability and cycle life objectives, refiners had already developed their own company specifications for refractory installations for the most important applications where unit availability is critical. A cottage industry of supporting quality control experts and inspectors evolved to help owner-operators reduce the gap between ideal and actual cycle life. Prior to the Vessel Refractory Task Group (the predecessor of the SCRM), manufacturers and installers largely had little say in these efforts and uniform industry standards were never developed or adopted.

To address this issue, the Vessel Refractory Task Group allowed for a broad representation of all the stake holders as part of the API’s spring and fall Refining Equipment Standards Meetings. Addressing the standards gap and noting the many similarities in owner-operator and OEM developed specifications, the API Task Force undertook the task of identifying useful industry practices and/or negotiating to agreement best fits for standards applications. API’s Refractory Installation Quality Control Guidelines—Inspection and Testing Monolithic Linings and Material was first issued in 1996 as a recommended practice. After a number of subsequent revisions, it was published as API Standard 936 in 2006, with a certification program beginning in 2004.

In addition to maintaining API Standard 936 and overseeing the certification program, in 2014 the Task Force reorganized under the Committee on Refinery Equipment (CRE) as the Refractory Project Group (RPG). As a project group, work expanded to ceramic fiber and brick quality control standards; unit specific applications, such as SRU and hydrogen furnaces; and technical reports, including this report. In response to this broadening recognition of the need to advance this technology for HPI applications, the CRE reclassified the group as a full subcommittee in 2016 and it now works under the title of the Subcommittee on Refractory Materials.

vii

Monolithic Refractories: Manufacture, Properties, and Selection

1. Scope

   This technical report covers the installation and dryout of monolithic refractory lining materials for Hydrocarbon Processing Industry (HPI) applications. It discusses the best practice procedures and techniques used in the installation of refractory concrete, as well as those for air and heat setting plastics and ramming mixes. In addition, it addresses the need for curing and dryout procedures to achieve successful results. This instruction is consistent with API Standard 936, which is the HPI industry standard for the installation quality control of monolithic refractories. API 936 also serves as a body of knowledge document for the API certification program for refractory practitioners.

   
   

   NOTE API TR 979 and API TR 980 are additional reports listed in Section 2, designed to provide a complete discussion of the monolithic refractory subject.

   
   

2. Referenced Documents

API 936, Refractory Installation Quality Control—Inspection and Testing Monolithic Refractory Linings and Materials

API TR 977, ASTM C704 Test Variability Reduced to Allow Further Optimization of Erosion Resistant Refractories for Critical Oil Refining Applications 1

API TR 979, Applications of Refractory Lining Materials 1

ASTM C16, Standard Test Method for Load Testing Refractory Shapes at High Temperatures

ASTM C20, Standard Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes by Boiling Water

ASTM C24, Standard Test Method for Pyrometric Cone Equivalent (PCE) of Fireclay and High-Alumina Refractory Materials

ASTM C92, Standard Test Methods for Sieve Analysis and Water Content of Refractory Materials

ASTM C115, Standard Test Method for Fineness of Portland Cement by the Turbidimeter

ASTM C129, Standard Specification for Nonloadbearing Concrete Masonry Units

ASTM C133, Standard Test Methods for Cold Crushing Strength and Modulus of Rupture of Refractories

ASTM C134, Standard Test Methods for Size, Dimensional Measurements, and Bulk Density of Refractory Brick and Insulating Firebrick

ASTM C150, Standard Specification for Portland Cement

ASTM C179, Standard Test Method for Drying and Firing Linear Change of Refractory Plastic and Ramming Mix Specimens

ASTM C181, Standard Test Method for Workability Index of Fireclay and High-Alumina Refractory Plastics

ASTM C191, Standard Test Methods for Time of Setting of Hydraulic Cement by Vicat Needle

ASTM C201, Standard Test Method for Thermal Conductivity of Refractories

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