GB/T 25138-2024 (English Version)

Standard No.: GB/T 25138-2024
Language: Chinese, Available in English version
Release Date: 2024
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Latest: GB/T 25138-2024
Replace: GB/T 25138-2010

Scope: This document specifies the brand, technical requirements, test methods, inspection rules, packaging, marking, transportation and storage of standard silica sand for calibrating foundry binders (referred to as standard silica sand for foundry). This document is applicable to the production and inspection of standard silica sand for calibrating foundry binders.

Introduction

Interpretation of GB/T 25138—2024 National Standard of the People's Republic of China

Item	GB/T 25138—2010	GB/T 25138—2024
Scope	Applicable to the production and inspection of standard silica sand for calibrating foundry binders.	New technical index requirements such as true density and pH value have been added.
Definition of terms	The specific chemical composition requirements of standard silica sand for foundry are not clearly defined.	Newly added Clause 3.1 to clarify the chemical composition and performance indicators of silica sand.
Grade Identification	The specific way of indicating the grade is not clear.	Four new chapters are added, stipulating that the grade is indicated as: ZBS90-53A-1.20, and explaining the meaning of each part in detail.

Background of Standard Revision and Analysis of Technical Evolution

Background:With the development of the foundry industry, the technical requirements for silica sand are increasing day by day. GB/T 25138-2010 can no longer meet the current testing needs, mainly reflected in:

It does not cover the new technical indicators added in modern casting technology, such as true density and conductivity.
The chemical composition requirements are not refined enough, and there is a lack of strict restrictions on impurity content.
The particle size composition detection method has not kept pace with the times, affecting the detection efficiency.

Detailed explanation of technical requirements

5.1 Chemical composition:

SiO₂ (mass fraction)/%	90～93
Impurity content (mass fraction)/%	Al₂O₃: <4.50；Fe₂O₃: <0.30；CaO+MgO: <0.40；K₂O: <2.00；Na₂O: <1.00

5.2 Particle size composition and average fineness:

Basic size of sieve hole (mm)	3.350～0.600；0.425；0.300；0.212；0.150；0.106；0.075；0.053～chassis
Residue (mass fraction)/%	<2；<13；18～23；40～46；13～17；<8；<1.5；<0.1（fine powder content）

5.3 Other technical performance indicators:

Mud content (mass fraction)/%	0.27～0.30
Water content (mass fraction)/%	≤0.20

GB/T 25138-2024 Referenced Document

GB/T 2684 Test methods for foundry sands and mixtures*， 2025-03-28 Update
GB/T 5071 Refractory materials.Determination of true density
GB/T 5611 foundry term
GB/T 6003.1 Test sieves—Technical requirements and testing—Part 1:Test sieves of metal wire cloth
GB/T 7143 Chemical analysis method of silica sand for foundry*， 2025-02-28 Update
GB/T 9442 Silica sand for casting

GB/T 25138-2024 history

2024 GB/T 25138-2024 Calibration of standard silica sand for casting binders
2010 GB/T 25138-2010 Standard sand for checking foundry binder