Exhibit 10.4

SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE CONFIDENTIAL TREATMENT
OF THOSE TERMS HAS BEEN REQUESTED. THE REDACTED MATERIAL HAS BEEN SEPARATELY
SUBMITTED TO THE SECURITIES AND EXCHANGE COMMISSION, AND THE TERMS HAVE BEEN
MARKED AT THE APPROPRIATE PLACE WITH THREE ASTERISKS (***).

September 6, 2016
Via Overnight Delivery and Email
Halliburton Energy Services, Inc.
Attention: Category Manager, Frac Sand
3000 N Sam Houston Pkwy E
Houston, TX 77032-3219

Dear Mr. Hillman:
Reference is hereby made to that certain Purchase Agreement by and between
Halliburton Energy Services, Inc., a Delaware corporation (“Halliburton”) and
Hi-Crush Operating LLC, a Delaware limited liability company (“Supplier” and,
together with Halliburton, the “Parties”), dated as of June 18, 2014, as amended
by that certain First Amendment to the Purchase Agreement, dated as of October
8, 2014 (as amended, the “Purchase Agreement”). All capitalized terms used but
not defined herein shall have the meanings ascribed to such terms in the
Purchase Agreement.

The Parties hereby agree that, during the period commencing on September 1, 2016
and ending August 31, 2017 or as earlier terminated pursuant to the terms of
this letter agreement (such period, the “Interim Term”), the following terms and
conditions shall apply and shall supersede any conflicting terms of the Purchase
Agreement during such Interim Term:

a)
During the Interim Term, the “Interim Price” shall be as follows: (i) FOB mine
pricing for 30/50, 40/70 and 100 Mesh Northern White frac sand purchased by
Halliburton under the Purchase Agreement shall be $*** per ton, (ii) FOB mine
pricing for 20/40 Northern White frac sand purchased by Halliburton under the
Purchase Agreement shall be $*** per ton, and (iii) delivered pricing at
Supplier’s terminal facilities for all Northern White frac sand purchased by
Halliburton during the Interim Term shall be the pricing in Exhibit B or as
mutually agreed upon by the Parties at the time of sale. The failure of the
Parties to agree upon pricing for Northern White frac sand delivered at
Supplier’s terminal facilities shall not relieve Halliburton of its obligation
to purchase the Monthly Minimum Interim Requirement as defined in section (b)
below. Additional terminal pricing not in Exhibit B will be mutually agreed to
between the Parties.

b)
During the Interim Term, Halliburton is obligated to buy from Supplier, and
Supplier is obligated to sell, at the Interim Price, *** tons of Northern White
frac sand each calendar month (the “Monthly Minimum Interim Requirement”).
Halliburton shall be entitled to count both FOB mine and terminal purchases
toward the Monthly Minimum Interim Requirement.

c)
During any calendar month of the Interim Term that Halliburton purchases at
least the Monthly Minimum Interim Requirement, Halliburton shall be eligible for
a rebate, to be paid by Supplier no later than forty-five (45) days following
the end of such calendar month, as follows:

i.
If Halliburton meets or exceeds the grade split percentage thresholds set forth
on Exhibit A for (A) 30/50 Premium Frac Sand, (B) 40/70 Premium Frac Sand, and
(C) 100 mesh sand, then Supplier shall pay Halliburton a rebate equal to $***
multiplied by the number of tons of Northern White frac sand purchased from
Supplier during such calendar month.

For the avoidance of doubt, Supplier shall not be obligated to pay a rebate to
Halliburton for any calendar month during which Halliburton fails to purchase at
least the Monthly Minimum Interim Requirement. Further, Halliburton’s failure to
meet the grade split percentage thresholds set forth on Exhibit A shall not be a
breach or default under this letter agreement and shall not in any way be a
factor in determining Halliburton’s compliance with its obligations set forth in
this letter agreement.
d)
In addition to Halliburton’s Monthly Minimum Interim Requirement, during each
three month quarter of the Interim Term, Halliburton shall use its best efforts
to divide its minimum required purchases between Supplier’s mines serviced by
the UP and CN railroads as follows: Halliburton shall use its best efforts to
purchase at least *** tons of its minimum required purchase of Northern White
frac sand under this side letter agreement during each three-month quarter from
Supplier’s mines serviced by the UP, and at least *** tons of its minimum
required purchase of Northern White frac sand under this side letter agreement
during each three-month quarter from Supplier’s mines serviced by the CN. In
addition to all other obligations set forth in this letter agreement,
Halliburton shall be deemed to have failed to comply with this letter agreement
if, for any three month quarter

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Exhibit 10.4

SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE CONFIDENTIAL TREATMENT
OF THOSE TERMS HAS BEEN REQUESTED. THE REDACTED MATERIAL HAS BEEN SEPARATELY
SUBMITTED TO THE SECURITIES AND EXCHANGE COMMISSION, AND THE TERMS HAVE BEEN
MARKED AT THE APPROPRIATE PLACE WITH THREE ASTERISKS (***).

of the Interim Term, Halliburton does not purchase at least *** tons of Northern
White frac sand from Supplier’s mines serviced by the UP and at least *** tons
of Northern White frac sand from Supplier’s mines serviced by the CN, unless
such variance was agreed to by Supplier in writing, resulted from an event of
Force Majeure, or resulted from the failure of Supplier to supply required
volumes consistent with ratios contemplated by this section (d) and due to no
fault of Halliburton.
e)
If Halliburton purchases Northern White frac sand in excess of the Monthly
Minimum Interim Requirement during any calendar month of the Interim Term, then
such excess tons of Northern White frac sand shall be counted towards
Halliburton’s Monthly Minimum Interim Requirement for a subsequent calendar
month during the Interim Term. Notwithstanding anything in this letter agreement
to the contrary, Supplier shall have no obligation to sell to Halliburton more
than *** tons of Northern White frac sand during any calendar month of the
Interim Term.

f)
If, after adding any applicable excess tons counted from a prior month in
accordance with section (e) above, Halliburton purchases less than the Monthly
Minimum Interim Requirement, but more than *** tons of Northern White frac sand,
from Supplier in any calendar month during the Interim Term (an “Interim
Shortfall Month”), then the “Interim Shortfall” shall be the amount by which the
Monthly Minimum Interim Requirement exceeds the amount of Northern White frac
sand actually purchased by Halliburton during such Interim Shortfall Month
including any applicable excess tons counted from a prior month in accordance
with section (e) above. Halliburton shall have sixty (60) days after the end of
such Interim Shortfall Month (the “Interim Cure Period”) to purchase tonnage of
Northern White frac sand in excess of the Monthly Minimum Interim Requirement to
make up for the Interim Shortfall. If the Interim Shortfall Month is the final
month of the Interim Term, Halliburton shall be entitled to the Interim Cure
Period for the Interim Shortfall for such Interim Shortfall Month, and any
rights or obligations that are determined hereunder upon the expiration of the
Interim Term shall be delayed until the conclusion of such Interim Cure Period
to determine if Halliburton’s obligations herein have been satisfied.

g)
If, after adding any applicable excess tons counted from a prior month in
accordance with section (e) above, Halliburton fails to purchase at least ***
tons of Northern White frac sand from Supplier in any calendar month during the
Interim Term (an “Interim Breach Month”), or if Halliburton fails to fully make
up an Interim Shortfall during the Interim Cure Period, then Halliburton shall
be deemed to have breached this letter agreement (a “Halliburton Breach”).
Halliburton shall have thirty (30) days after written notice from Supplier to
cure a Halliburton Breach by purchasing tonnage of Northern White frac sand from
Supplier in excess of the Monthly Minimum Interim Requirement in an amount equal
to (i) the difference between the Monthly Minimum Interim Requirement and the
number of tons of Northern White frac sand purchased by Halliburton from
Supplier during the Interim Breach Month including any applicable excess tons
counted from a prior month in accordance with section (e) above or (ii) the
uncured Interim Shortfall, as applicable. If the time period to cure a
Halliburton Breach provided above extends past the end of the Interim Term,
Halliburton shall be entitled to the full cure period for such Halliburton
Breach, and any rights or obligations that are determined hereunder upon the
expiration of the Interim Term shall be delayed until the conclusion of such
cure period to determine if Halliburton’s obligations herein have been
satisfied. If Halliburton fails to cure a Halliburton Breach or other
non-compliance hereunder within thirty (30) days after written notice thereof
from Supplier, then this letter agreement and all terms and conditions hereunder
shall automatically terminate, and all terms and conditions of the Purchase
Agreement shall be reinstated in full force and effect. Notwithstanding the
foregoing, if Halliburton has more than one (1) Halliburton Breach during the
Interim Term, Supplier shall have the right to immediately terminate this letter
agreement by giving written notice of termination to Halliburton and, in the
event of such termination, all terms and conditions of the Purchase Agreement
shall be reinstated in full force and effect. Supplier hereby reserves all
rights and remedies under the Purchase Agreement, including without limitation,
any and all rights, remedies and claims which existed for Purchase Shortfalls
and Makewhole Payment liability as of the effective date hereof.

The Parties further agree that on August 31, 2017, provided that Halliburton has
fully complied with its obligations set forth in this letter agreement during
the Interim Term, including but not limited to purchasing Northern White frac
sand from Supplier in accordance with the volume requirements and the prices set
forth herein, then (i) the Purchase Agreement shall automatically terminate,
(ii) any and all claims whatsoever by Supplier, including but not limited to any
Supply Shortfall or Purchase Shortfall (or monetary obligation with respect
thereto, including Makewhole Payment liability) existing under the Purchase
Agreement as of August 31, 2017, as well as any and all claims relating to
outstanding invoices asserted by D & I Silica, LLC in

Page 2 of 6

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Exhibit 10.4

SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE CONFIDENTIAL TREATMENT
OF THOSE TERMS HAS BEEN REQUESTED. THE REDACTED MATERIAL HAS BEEN SEPARATELY
SUBMITTED TO THE SECURITIES AND EXCHANGE COMMISSION, AND THE TERMS HAVE BEEN
MARKED AT THE APPROPRIATE PLACE WITH THREE ASTERISKS (***).

regards to transload fees, switch fees and storage fees in the amount of $***
shall be fully and forever waived by Supplier, (iii) any and all claims
whatsoever by Halliburton against Supplier or D & I Silica, LLC under the
Purchase Agreement or any other contract or agreement between the Parties or
between Halliburton and D & I Silica, LLC including, without limitation, any
claim against either D & I Silica, LLC or Supplier for private cars fees or for
alleged overcharging of transload fees, switching fees, demurrage, or for
inventory loss shall be fully and forever waived by Halliburton and (iv) the
Parties shall use their best efforts to negotiate a new or revised agreement for
the purchase and sale of frac sand taking into consideration then prevailing
market conditions. In the event that Halliburton shall fail to comply with its
obligations set forth in this letter agreement during the Interim Term, the
provisions of this paragraph shall become null and void and, in addition to the
rights and remedies set forth in section (g) above, the Parties shall be
entitled to pursue any and all claims or remedies available to them with regard
to any claim by either Party which may exist on the effective date of this
letter agreement.

Except as otherwise expressly modified herein, all terms and conditions of the
Purchase Agreement shall remain in full force and effect.

All information contained in this letter agreement, including the existence of
such letter agreement, is deemed confidential and shall not be disclosed to any
third party; provided that the provisions set forth in Article 6 of the Purchase
Agreement shall apply to the information contained herein as if such information
was Confidential Information. This letter agreement may be executed in any
number of counterparts, each of which shall be deemed to be an original
instrument, but all of which taken together shall constitute one instrument. A
signature page to this letter agreement that contains a copy of a party’s
signature and that is sent by such party or its agent with the apparent
intention (as reasonably evidenced by the actions of such party or its agent)
that it constitute such party’s execution and delivery of this letter agreement,
including a document sent by facsimile transmission or by email in portable
document format (pdf), shall have the same effect as if such party had executed
and delivered an original of this letter agreement. This letter agreement shall
be governed by and construed in accordance with the internal laws of the State
of Texas without regard to conflict of law principles and shall be binding on
the parties hereto and their successors and assigns.

[Signature Page Follows.]

Page 3 of 6

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Exhibit 10.4

SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE CONFIDENTIAL TREATMENT
OF THOSE TERMS HAS BEEN REQUESTED. THE REDACTED MATERIAL HAS BEEN SEPARATELY
SUBMITTED TO THE SECURITIES AND EXCHANGE COMMISSION, AND THE TERMS HAVE BEEN
MARKED AT THE APPROPRIATE PLACE WITH THREE ASTERISKS (***).

In Witness Whereof, this letter agreement is executed by the parties hereto as
of the date first set forth above.
Best regards,
Signature: /s/ Robert E. Rasmus
Printed Name: Robert E. Rasmus
Title: Chief Executive Officer
Hi-Crush Operating LLC

Signature: /s/ Robert E. Rasmus
Printed Name: Robert E. Rasmus
Title: Chief Executive Officer
D & I Silica, LLC

AGREED TO AND ACKNOWLEDGED:

HALLIBURTON ENERGY SERVICES, INC.

Signature: /s/ Authorized Person
Printed Name: Authorized Person
Title: Authorized Officer

Signature: /s/ Authorized Person
Printed Name: Authorized Person
Title: Authorized Officer

Page 4 of 6

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Exhibit 10.4

SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE CONFIDENTIAL TREATMENT
OF THOSE TERMS HAS BEEN REQUESTED. THE REDACTED MATERIAL HAS BEEN SEPARATELY
SUBMITTED TO THE SECURITIES AND EXCHANGE COMMISSION, AND THE TERMS HAVE BEEN
MARKED AT THE APPROPRIATE PLACE WITH THREE ASTERISKS (***).

EXHIBIT A
 
Grade Split %
 
UP Origin
CN Origin
20/40
***%

***%

30/50
***%

***%

40/70
***%

***%

100
***%

***%

Total
100
%
100
%

Page 5 of 6

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Exhibit 10.4

SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE CONFIDENTIAL TREATMENT
OF THOSE TERMS HAS BEEN REQUESTED. THE REDACTED MATERIAL HAS BEEN SEPARATELY
SUBMITTED TO THE SECURITIES AND EXCHANGE COMMISSION, AND THE TERMS HAVE BEEN
MARKED AT THE APPROPRIATE PLACE WITH THREE ASTERISKS (***).

EXHIBIT B
Destination
Price ($/Ton)
Smithfield, PA
$***
Mingo Junction, OH
$***
Pittston, PA
$***
Wellsboro, PA
$***
Binghamton, NY
$***
Kittaning, PA
$***
Natchitoches, LA
$***
Evans, CO
$***

Page 6 of 6