Exhibit 3.18

                      RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                            GREAT SALT LAKE MINERALS
                            AND CHEMICALS CORPORATION

                        Under Section 245 of the General
                    Corporation Law of the State of Delaware


               GREAT SALT LAKE MINERALS AND CHEMICALS CORPORATION, a corporation
organized and existing under and by virtue of the General Corporation Law of the
State of Delaware (the "Corporation"), DOES HEREBY CERTIFY:

               FIRST: That the original Certificate of Incorporation of the
Corporation was filed with the Secretary of State, Dover, Delaware, on the 7th
day of February, 1967 and that the Restated Certificate of Incorporation of the
Corporation was filed with the Secretary of State, Dover, Delaware, on the 3rd
day of March, 1989.

               SECOND: That the Restated Certificate of Incorporation of the
Corporation has been duly adopted in accordance with the provisions of Section
141(f), 228(a), 242 and 245 of the General Corporation Law of the State of
Delaware.

               THIRD: That the text of the Certificate of Incorporation of the
Corporation is hereby restated by this Certificate, to read in full, as follows:



                      RESTATED CERTIFICATE OF INCORPORATION
                                      -of-
                          GREAT SALT LAKE MINERALS AND
                              CHEMICALS CORPORATION


                                     -oo0oo-

               FIRST: The name of the Corporation in Great Salt Lake Minerals
and Chemicals Corporation (hereinafter sometimes called the "Corporation").

               SECOND: The address of the Corporation's registered office in the
State of Delaware is Corporation Trust Center, 1209 Orange Street, City of
Wilmington, County of New Castle, State of Delaware 19801. The name of its
registered agent at such address in The Corporation Trust Company.

               THIRD: The nature of the business or purposes to be conducted or
promoted are to engage in any lawful act or activity for which corporations may
be organized under the General Corporation Law of the State of Delaware.

               FOURTH: The total number of shares of stock which the Corporation
shall have authority to issue is 30,000 shares, consisting of:

               1. 20,000 shares of Preferred Stock, par value $.01 per share
("Preferred Stock"); and

               2. 10,000 shares of Common Stock, par value $.01 per share
("Common Stock").

                                 PREFERRED STOCK

Part 1.        Dividends.
               ---------

               1A. General Obligation. When, as and if declared by the Board of
                   ------------------
Directors of the Corporation, and to the extant permitted under the General
Corporation Law of the State of Delaware, the Corporation will pay preferential
cumulative dividends out of funds legally available for the payment of dividends
to the holders of Preferred Stock at the times and in the



                                       -2-

amounts provided for in this Part 1. Except as otherwise provided herein,
cumulative dividends on Preferred Stock will accrue on a daily basis (computed
on the basis of a 360-day year of twelve 30-day months) at the rate of 14% of
the Stated Value per year (subject to adjustment as provided in Part 5), from
and including the date of issuance of such Preferred Stock to but excluding the
date on which the Redemption Price of such Preferred Stock is paid. Such
dividends will accrue and be cumulative whether or not they have been declared
and whether or not there are profits, surplus or other funds of the Corporation
legally available for the payment of dividends. The data on which the
Corporation initially issues any share of Preferred Stock will be deemed to be
its "date of issuance" regardless of the number of times transfer of such share
of Preferred Stock is made an the stock records of the Corporation, and
regardless of the number of certificates which may be issued to evidence such
share of Preferred Stock.

               1B. Payment of Dividends. Dividends accrued on the Preferred
                   --------------------
Stock shall be payable on March 31, June 30, September 30 and December 31 in
each year (each such date being herein referred to as a "Dividend Reference
Date"), commencing on Juno 30, 1990. Such dividends shall be paid to the holders
of record at the close of business on the data specified by the Board of
Directors at the time such dividend is declared; provided, however, that such
                                                 --------  -------
date shall not be more than ten days prior to the respective Dividend Reference
Date. To the extent not paid on any Dividend Reference Date, all dividends which
have accrued on each share of Preferred Stock then outstanding during the period
from and including the immediately preceding Dividend Reference Date (or from
the date of original issue of the Preferred Stock in the case of the initial
Dividend Reference Date) to such Dividend Reference Date will be added to the
Stated Value of such share of Preferred Stock and will remain a part thereof
until such dividends are paid. Any dividends payable with respect to the
Preferred Stock during the first three years after the date of issuance may be
paid (subject to restrictions under applicable state law), in the sole
discretion of the Board of Directors, in cash or by issuing additional fully
paid and nonassessable shares of Preferred Stock, having an aggregate Stated
Value equal to the amount of such dividend, and the issuance of such additional
shares shall constitute full payment of such dividend. Dividends payable with
respect to the Preferred Stock after the first three years after the date of
issuance are payable only in cash. All shares of Preferred Stock which may be
issued as a dividend with respect to the Preferred Stock will thereupon be duly
authorized, validly issued, fully paid and nonassessable and free of all lions
and charges.

               1C. Distribution of Partial Dividend Payments. If at any time the
                   -----------------------------------------
Corporation distributes less than the total amount of dividends then accrued
with respect to Preferred Stock, such payment will be distributed among the
holders of Preferred Stock so that an equal amount will be paid (as nearly as
possible) with respect to each outstanding share of Preferred Stock.

               1D. Priority. So long as any Preferred Stock remains outstanding,
                   --------
neither the Corporation nor any of its subsidiaries will redeem, purchase or
otherwise acquire any Junior Securities, nor will the Corporation declare or pay
any dividend or make any distribution upon Junior Securities in excess of
$50,000 per year if immediately after such redemption, purchase, acquisition,
dividend or distribution any Event of Noncompliance of the type described in
paragraphs (1) or (2) of Subpart 5A would exist with respect to the Preferred
Stock, or if the Corporation shall have failed to pay the full amount of
dividends accrued on the Preferred Stock as of the most recent Dividend
Reference Date.



                                       -3-

               1E. Limitation on Dividend Restrictions. The Corporation shall
                   -----------------------------------
not, and shall not permit any subsidiaries to, agree to any provision in any
agreement (other than those in the Credit Agreement on the date hereof or in
connection with any refinancing or refunding thereof which is no more
restrictive than the restrictions contained in the Credit Agreement on the date
hereof), which would impose any restrictions on the Corporation's right to
declare and pay dividends an or make any mandatory redemption of Preferred
Stock.

Part 2.        Liquidation.
               -----------

               Upon any voluntary or involuntary liquidation, dissolution or
winding up of the affairs of the Corporation, the holders of shares of Preferred
Stock then outstanding will be entitled to be paid out of the assets of the
Corporation available for distribution to stockholders (whether from capital,
surplus or earnings), before any distribution or payment is made upon any Junior
Securities of the Corporation, an amount in cash equal to the aggregate
Liquidation Value of all Preferred Stock outstanding to the date fixed for
liquidation, dissolution or winding up. The holders of Preferred Stock will not
be entitled to any further payment. If, upon any such liquidation, dissolution
or winding up of the Corporation, the assets of the Corporation to be
distributed among the holders of Preferred Stock are insufficient to permit
payment to such holders of the aggregate amount which they are entitled to be
paid, then the entire assets of the Corporation to be distributed to such
holders will be distributed ratably among such holders based upon the aggregate
Liquidation Value of the Preferred Stock hold by each such holder. The
Corporation will mail written notice of such liquidation, dissolution or winding
up, not less than 30 days prior to the payment date stated therein, to each
record holder of Preferred Stock. Neither the consolidation or merger of the
Corporation into or with any other corporation or corporations, nor the sale or
transfer by the Corporation of all or any part of its assets, nor the reduction
of the capital stock of the Corporation, will be deemed to be a liquidation,
dissolution or winding up of the Corporation within the meaning of this Part 2
unless such consolidation, merger, sale or transfer shall be in connection with
a plan of liquidation, dissolution or winding up of the business of the
Corporation.

Part 3.        Redemptions.
               -----------

               3A. Redemption at the Option of the Corporation. Subject to the
                   -------------------------------------------
legal availability of funds, any contractual restrictions then binding an the
Corporation (including restrictions under the Credit Agreement) and applicable
state law, the Corporation may redeem at its option, at any time, all or any
portion of the Preferred Stock then outstanding at a price per share of
Preferred Stock equal to the Redemption Price.

               3B  Mandatory Redemption. At the earlier of (i) March 30, 2000,
                   --------------------
(ii) the merger of the Corporation with or into another corporation whereby the
Corporation is not the corporation surviving the merger other than a merger with
a subsidiary of North American Salt Company, (iii) the sale of all or
substantially all of the assets of the Corporation or (iv) the date on which the
preferred stock of North American Salt Company is redeemed or required to be
redeemed pursuant to the terms of the Certificate of Incorporation of North
America Salt Company, the Corporation will redeem all of the shares of Preferred
Stock than outstanding at a price per share of Preferred Stock equal to the
Redemption Price.



                                       -4-

               3C. Redemption Price. For each share of Preferred Stock which is
                   ----------------
to be redeemed pursuant to this Part 3, the Corporation will be obligated on (i)
the date designated by the Corporation for redemption of Preferred Stock in
connection with Subpart 3A or (ii) the date any of the events specified in the
first sentence of Subpart 3B occur (each such date being herein referred to as a
"Redemption Date" as further defined in Part 6) to pay to the holder thereof
(upon surrender by such holder at the Corporation's principal office of the
certificate representing such shares of Preferred Stock) an amount in cash equal
to the Redemption Price. If the funds of the Corporation legally available for
redemption of Preferred Stock on any Redemption Date are insufficient to redeem
the total number of shares of Preferred Stock to be redeemed on such date, those
funds which are legally available will be used to redeem the maximum possible
number of shares of Preferred Stock ratably among the holders of the Preferred
Stock to be redeemed. At any time thereafter when additional funds of the
Corporation are legally available for the redemption of Preferred Stock, such
funds will immediately be used to redeem the balance of the Preferred Stock
which the Corporation has become obligated to redeem on any Redemption Date but
which it has not redeemed.

               3D. Notice of Redemption. The Corporation will mail written
                   --------------------
notice of each redemption of Preferred Stock pursuant to Subpart 3A or 3B to
each record holder thereof, not more than 60 nor less than 10 days prior to the
date on which such redemption is to be made at such holder's address as the same
appears an the stock register of the Corporation; provided, however, that no
                                                  --------  -------
failure to give such notice nor any defect therein shall affect the validity of
the proceeding for the redemption of any shares of Preferred Stock to be
redeemed except as to the holder to whom the Corporation has failed to give said
notice or except as to the holder whose notice was defective. Each such notice
shall state: (i) the Redemption Date; (ii) the number of shares of Preferred
Stock to be redeemed and, if less than all the shares held by such holder are to
be redeemed, the number of shares of Preferred Stock hold by such holder to be
redeemed; (iii) the Redemption Price; and (iv) the place or places where
certificates for such shares are to be surrendered for payment of the Redemption
Price. In case fewer than the total number of shares of Preferred Stock
represented by any certificate are redeemed pursuant to this Part 3, a new
certificate representing the number of unredeemed shares of Preferred Stock will
be issued to the holder thereof without cost to such holder promptly after
surrender of the certificate representing the redeemed shares of Preferred
Stock.

               3E. Determination of the Number of Shares of Each Holder's
                   ------------------------------------------------------
Preferred Stock to be Redeemed. The number of shares of Preferred Stock to be
- ------------------------------
redeemed from each holder thereof in partial redemptions by the Corporation
under Subpart 3A will be the number of shares of Preferred Stock determined by
multiplying the total number of shares of Preferred Stock desired to be redeemed
times a fraction, the numerator of which will be the total number of shares of
Preferred Stock than hold by such holder and the denominator of which will be
the total number of shares of Preferred Stock then outstanding.

               3F. Dividends After Redemption Date. No share of Preferred Stock
                   -------------------------------
is entitled to any dividends accruing after its Redemption Date. On such
Redemption Date all rights of the holder of such share of Preferred Stock will
cease, and such share of Preferred Stock will not be deemed to be outstanding.



                                       -5-

          3G.  Redeemed or Otherwise Acquired Shares. Any shares of Preferred
               -------------------------------------
Stock which are redeemed or otherwise acquired by the Corporation or a
subsidiary will be canceled and will not be reissued, sold or transferred.

Part 4.   Voting Rights.
          -------------

          The outstanding shares of Preferred Stock shall have no voting rights
except as required by law and such additional voting rights as are set forth
below.

          4A.  No amendment, modification or waiver will be binding or effective
with respect to any provision of the Preferred Stock Section of Article Fourth
of this Restated Certificate of Incorporation unless approved by the affirmative
vote of the holders of at least a majority of the outstanding shares of
Preferred Stock voting together as a separate class.

          4B.  In addition to any other vote or consent of stockholders required
herein, the By-laws of the Corporation or by law, the affirmative vote of all
the holders of the outstanding shares of Preferred Stock, voting together as a
separate class, shall be necessary to change the rate or time of payment of any
dividends on, the time or amount of any redemption of, or the amount of any
payments upon liquidation of the Corporation with respect to, the priorities
afforded by the provisions of Subpart 1D for the benefit of, shares of Preferred
Stock or to amend Part 3 or this Part 4.

          4C.  The affirmative vote of the holders of at least a majority of the
outstanding shares of Preferred Stock voting together as a separate class shall
be necessary to:

               (i)   increase the number of authorized shares of Preferred Stock
     or authorize or issue any additional shares of any series of Preferred
     Stock or any shares of capital stock of the Corporation of any class, or
     any security or obligations convertible into any capital stock of the
     Corporation of any class, in each case ranking on a parity with or senior
     to the Preferred Stock as to distribution of assets in liquidation or in
     right of payment of dividends;

               (ii)  permit the sale, lease or conveyance of all or
     substantially all of the property or business of the Corporation or the
     consolidation or, except with a subsidiary of North American Salt Company,
     merger of the Corporation with or into any other corporation unless in any
     of the circumstances set forth above the Corporation shall have exercised
     its option to redeem all of the shares of Preferred Stock pursuant to
     Subpart 3A out of legally available funds; or

               (iii) change by amendment to the Corporation's Certificate of
     Incorporation or otherwise the terms or provisions of the Preferred Stock
     so as to adversely affect the powers, special rights and preferences of the
     holders thereof.

Part 5.   Events of Noncompliance.
          -----------------------

          5A.  Definition. An Event of Noncompliance ("Event of Noncompliance")
               ----------
will be deemed to have occurred with respect to Preferred Stock if:



                                       -6-

          (1) the Corporation fails to pay on any Dividend Reference Date the
full amount of dividends then accrued; or

          (2) the Corporation fails to make any redemption payment with respect
to the Preferred Stock which it is obligated to make.

5B.       Consequences of Event of Noncompliance.
          --------------------------------------

          (1) From and after the occurrence of an Event of Noncompliance
specified in Subpart 5A(1) above, the rate at which dividends on the Preferred
Stock provided for herein accrue will be increased to 14.25% per annum of the
Stated Value thereof, and such dividend accrual rate will further increase by
 .25% from and after the ninetieth day following the occurrence of such Event of
Noncompliance and will further increase by 25% from and after the end of each
succeeding 90 day period thereafter an long as there is continuing in existence
any such Event of Noncompliance, but as not to a rate in excess of l7% per
annum. From and after the occurrence of an Event of Noncompliance specified in
Subpart 5A(2) above, the rate at which dividends on the Preferred Stock provided
for herein accrue will be increased to 17% per annum of the Stated Value thereof
go long as there is continuing in existence any such Event of Noncompliance.
From and after such time as there is no such Event of Noncompliance continuing
in existence, dividends on the Preferred Stock shall accrue at the rate provided
for in Part I until the occurrence of another Event of Noncompliance, whereupon
the rate at which dividends on the Preferred Stock will accrue will be increased
in the manner and subject to the conditions set forth in this Subpart 5B.

          (2) If any Event of Noncompliance exists, each holder of Preferred
Stock will also have any other rights which such holder may have been afforded
under any contract or agreement at any time and any other rights which such
holder may have pursuant to applicable law.

Part 6. Definitions.
        -----------

          For purposes of Article Fourth of this Restated Certificate of
Incorporation, the following terms shall have the following meanings:

          "Credit Agreement" means the Credit Agreement dated as of March 3,
           ----------------
1989 among the Corporation, each of the banks that is a signatory thereto and
The Chase Manhattan Bank (National Association) as agent, and the agreements
entered into in connection therewith, as the same may be amended, endorsed,
supplemented or otherwise modified from time to time.

          "Dividend Reference Date" shall have the meaning set forth in Subpart
           -----------------------
1B.

          "Event Of Noncompliance" shall have the meaning set forth in Part 5.
           ----------------------

          "Junior Security" means any equity security of any kind which the
           ---------------
Corporation or any subsidiary at any time issues or is authorized to issue other
than the Preferred Stock.



                                       -7-

          "Liquidation Value" of any share of Preferred Stock as of any
           -----------------
particular date will be equal to the sum of $1,000 plus an amount in cash equal
to all accrued but unpaid dividends (whether or not earned or declared) thereon.

          "Person" means an individual, a partnership, a corporation, a trust,
an estate, a joint venture, an unincorporated organization or a government or
any department or agency thereof.

          "Redemption Date" as to any share of Preferred Stock means the date
specified in the notice of any redemption at the Corporation's option, or the
applicable date specified heroin in the case of a redemption pursuant to the
provisions of Subpart 3B; provided that no such date will be a Redemption Date
                          --------
unless the Redemption Price is paid in full in cash on such date, and if not so
paid in full, the Redemption Date will be the date on which such Redemption
Price is fully paid as permitted and required by Article Fourth of this Restated
Certificate of Incorporation.

          "Redemption Default" shall have the meaning set forth in Subpart 4D.
           ------------------

          "Redemption Price" for any share of Preferred Stock as of any
           ----------------
particular date will be an amount equal to the Liquidation Value of such share
of Preferred Stock.

          "Stated Value" of any share of Preferred Stock as of any particular
           ------------
date will be equal to the sum of $1,000 plus an amount equal to all unpaid
dividends required to be added thereto as provided in Subpart 1B.

Part 7.   Notices.
          -------

          All notices referred to herein, except as otherwise expressly
provided, will be made by registered or certified mail, return receipt
requested, postage prepaid and will be deemed to have been given when so mailed.

Part 8.   Registration of Transfer.
          ------------------------

          The Corporation shall keep at its principal office (or ouch other
place as the Corporation reasonably designates) a register for the registration
of shares of Preferred Stock of the Corporation. Upon the surrender of any
certificate representing shares of Preferred Stock at such place, the
Corporation shall, at the request of the registered holder of such certificate,
execute and deliver a new certificate or certificates in exchange therefor
representing in the aggregate the number of shares of Preferred Stock
represented by the surrendered certificate (and the Corporation forthwith shall
cancel such surrendered certificate), subject to the requirements of applicable
securities laws and to any restrictions on transfer (including without
limitation, those referred to in any legend on the certificate to surrendered).
Each such new certificate shall be registered in such name and shall represent
such number of shares of Preferred Stock as is requested by the holder of the
surrendered certificate and shall be substantially identical in form to the
surrendered certificate. The issuance of new certificates shall be made without
charge to the holders of the surrendered certificates for any issuance tax in
respect thereof or other cost incurred by the Corporation in connection with
such issuance; provided, however, that the Corporation shall not be required to
               --------  -------
pay any tax which may be payable in respect of any transfer



                                       -8-

involved in the issuance and delivery of any certificate in a name other than
that of the holder of the surrendered certificate.

Part 9.   Replacement.
          -----------

          Upon receipt of evidence reasonably satisfactory to the Corporation
(an affidavit of the registered holder shall be satisfactory) of the ownership
and the loss, theft, destruction or mutilation of any certificate evidencing one
or more shares of Preferred Stock and, in the case of any such loss, theft or
destruction, upon receipt of indemnity reasonably satisfactory to the
Corporation (provided that if the holder is an institution, its own unsecured
agreement of indemnity shall be satisfactory), or, in the case of any such
mutilation, upon surrender of such certificate, the Corporation shall (at its
expense) execute and deliver in lieu of such certificate a now certificate of
like kind representing the number of shares of Preferred Stock represented by
such lost, stolen, destroyed or mutilated certificate and dated the date of such
lost, stolen, destroyed or mutilated certificate.

          FIFTH: The following additional provisions are inserted for the
management of the business and for the conduct of the affairs of the
Corporation, and for the creation, definition, limitation and regulation of the
powers of the Corporation, the directors and the stockholders:

          1. Election of directors need not be by written ballot. The Board of
Directors shall have power to make, alter, amend and repeal the By-Laws of the
Corporation and to fix the compensation of directors for services in any
capacity.

          2. Any director may be removed at any time, with or without cause,
upon the affirmative vote of the holders of a majority of the stock of the
Corporation at that time having voting power for the election of directors;
provided, however, that no director who shall have been elected by the holders
- --------  -------
of a separate class of stock shall be removed under the provisions of this
subdivision except upon the affirmative vote of the holders of a majority of the
class whose holders elected him, if such holders are then entitled to vote for
the election of directors.

          3. Any corporate action, with respect to which the vote of the
stockholders at a meeting thereof is required or permitted by any provision of
the General Corporation Law of the State of Delaware or of the Certificate of
Incorporation or the By-Laws of the Corporation, is authorized to be taken and
may be taken without that vote and meeting, and that vote and meeting may be
dispensed with, upon the written consent of the holders of a majority (or, if
with respect to a particular corporate action where the General Corporation Law
of the State of Delaware or the Certificate of Incorporation or the By-Laws of
the Corporation specifies a greater percentage, by the holders of that greater
percentage) of the stock; that would have been entitled to vote upon that action
if a meeting were held. Prompt notice shall be given to all stockholders of the
taking of any corporate action pursuant to the provisions of this paragraph 3
unless that action has been consented to in writing by the holders of all of the
stock that would have been entitled to vote upon that action if a meeting were
held.

          4. A director of the Corporation shall not be personally liable to the
Corporation or its stockholders for monetary damages for breach of fiduciary
duty as a director, except for liability (i) for any broach of the director's
duty of loyalty to the Corporation or its stockholders,



                                       -9-

(ii) for acts or omissions not in good faith or which involve intentional
misconduct or a knowing violation of law, (iii) under Section 174 of the
Delaware General Corporation Law, or (iv) for any transaction from which the
director derived an improper personal benefit.

          5. The Corporation shall not be governed by Section 203 of the
Delaware General Corporation Law.

          SIXTH: The Corporation shall indemnify any person who was or is a
party, or is threatened to be made a party, to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative, including an action by or in the right of the Corporation, by
reason of the fact that he, or the person whose legal representative he is, (1)
is or was a stockholder, director, officer, employee or agent of the Corporation
(including the incorporator thereof), or (2) is or was serving at the request of
the Corporation as a director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other enterprise, or (3) is or
was a director, officer or employee of the Corporation serving at the request of
the Corporation as a fiduciary of an employee benefit plan or trust maintained
for the benefit of employees of the Corporation or employees of any such other
enterprise, partnership, joint venture, trust, or other enterprise, against
judgments, fines, penalties, amounts paid in settlement, and expanses, including
attorneys' fees actually and reasonably incurred by him and the person whose
legal representative he is, in connection with such action, suit or proceeding,
or any appeal therein, to the fullest extent permitted by law.

          Expenses which may be indemnifiable under this Section incurred in
defending an action, suit or proceedings may be paid by the Corporation in
advance of the final disposition of such action, suit or proceeding as
authorized by the Board of Directors upon agreement by or on behalf of the
stockholder, director, officer, employee or agent, or his legal representative,
to repay such amount if he is later found not entitled to be indemnified by the
Corporation as authorized in this section.

          The Corporation shall not indemnify any stockholder, director,
officer, employee or agent against judgments, lines, amounts paid in settlement
and expenses, including attorneys' fees, to an extent greater than that
authorized by this section, but the Corporation may procure insurance providing
greater indemnification and may share the premium cost with any stockholder,
director, officer, employee or agent on such basis as may be agreed upon.



          IN WITNESS WHEREOF, the Corporation has caused this Certificate to be
signed by Anthony J. Petrocelli, its Vice President, and attested by Richard J.
Donahue, its Vice President and Secretary, this 29/th/ day of March, 1990.

                                    GREAT SALT LAKE MINERALS
                                     & CHEMICALS CORPORATION

                                     By: _______________________________
                                         Name:  Anthony J. Petrocelli
                                         Title: Vice President


ATTEST:

By: _______________________
    Name:  Richard J. Donahue
    Title: Vice President and
           Secretary