**Exhibit 31.2**

**AMCOL INTERNATIONAL CORPORATION**

**CERTIFICATIONPursuant to Rule 13a – 14(a) / 15d-14(a)**

|   | I, Gary L. Castagna, certify that:                                                                                                                                                                                                                                                                                                                |
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| 1.     | I have reviewed this quarterly report on Form 10-Q of AMCOL   International Corporation;                                                                                                                                                                                                                                                          |
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| 2.     | Based on my knowledge, this report does not   contain any untrue statement of a material fact or omit to state a material   fact necessary to make the statements made, in light of the circumstances   under which such statements were made, not misleading with respect to the   period covered by this report;                                |
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| 3.     | Based on my knowledge, the financial   statements, and other financial information included in this report, fairly   present in all material respects the financial condition, results of   operations and cash flows of the registrant as of, and for, the periods   presented in this report;                                                   |
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| 4.     | The registrant’s other certifying officer   and I are responsible for establishing and maintaining disclosure controls   and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and   internal control over financial reporting (as defined in Exchange Act Rules   13a-15(f) and 15d-15(f)) for the registrant and have: |
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|   | a)                                                                                                                                                                                                                                                                                                                                                | Designed   such disclosure controls and procedures, or caused such disclosure controls   and procedures to be designed under our supervision, to ensure that material   information relating to the registrant, including its consolidated   subsidiaries, is made known to us by others within those entities,   particularly during the period in which this report is being prepared; |
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|   | b)                                                                                                                                                                                                                                                                                                                                                | Designed   such internal control over financial reporting, or caused such internal   control over financial reporting to be designed under our supervision, to   provide reasonable assurance regarding the reliability of financial reporting   and the preparation of financial statements for external purposes in   accordance with generally accepted accounting principles; |
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|   | c)                                                                                                                                                                                                                                                                                                                                                | Evaluated   the effectiveness of the registrant’s disclosure controls and procedures and   presented in this report our conclusions about the effectiveness of the   disclosure controls and procedures, as of the end of the period covered by   this report based on such evaluation;    and |
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|   | d)                                                                                                                                                                                                                                                                                                                                                | Disclosed   in this report any change in the registrant’s internal control over financial   reporting that occurred during the registrant’s most recent fiscal quarter   (the registrant’s fourth fiscal quarter in the case of an annual report) that   has materially affected, or is reasonably likely to materially affect, the   registrant’s internal control over financial reporting; and |
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| 5.     |                                                                                                                                                                                                                                                                                                                                              | The registrant’s other certifying officer   and I have disclosed, based on our most recent evaluation of internal control   over financial reporting, to the registrant’s auditors and the audit   committee of the registrant’s board of directors (or persons performing the   equivalent function): |
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|   | a)                                                                                                                                                                                                                                                                                                                                                | All   significant deficiencies and material weaknesses in the design or operation   of internal control over financial reporting which are reasonably likely to   adversely affect the registrant’s ability to record, process, summarize and   report financial information; and Any fraud, whether or not material, that   involves management or other employees who have a significant role in the   registrant’s internal control over financial reporting. |

| Date:  August   8, 2006 |   | /s/ Gary L.   Castagna                                                            |
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|                              |   | Gary L.   Castagna                                                                |
|                              |   | Senior Vice   President, Chief Financial Officer and Principal Accounting Officer |

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