SUMMARY

         This summary highlights information contained elsewhere in this prospectus. You should read the entire prospectus carefully, including the historical and pro forma financial statements and the notes to those financial statements, before investing in our common units. The information presented in this prospectus assumes (1) an initial public offering price of $        per common unit (the mid-point of the price range set forth on the cover page of this prospectus) and (2) unless otherwise indicated, that the underwriters' option to purchase additional common units is not exercised and that the common units otherwise issuable upon the exercise of such option are instead issued to the owners of our general partner. You should read "Risk Factors" for information about important risks that you should consider before buying our common units.

         OCI Resources LP, or OCI Resources, has been recently formed by OCI Wyoming Holding Co., or OCI Holdings, to hold, at the closing of this offering, a 50.5% controlling general partner interest and a 0.5% limited partner interest in OCI Wyoming, L.P., or, including any of its subsidiaries, OCI Wyoming. OCI Wyoming owns and operates a trona ore mining and soda ash production facility in the Green River Basin of Wyoming. This general partner interest in OCI Wyoming is currently held by OCI Holdings. OCI Chemical Corporation, or OCI Chemical, owns 100% of the capital stock of OCI Holdings. OCI Chemical is a wholly owned subsidiary of OCI Enterprises Inc., or Enterprises. Enterprises is a majority owned subsidiary of OCI Company Ltd., or OCI Company. Natural Resource Partners L.P., or, including its affiliates, NRP, an unaffiliated third party, owns a 48.5% general partner interest and a 0.5% limited partner interest in OCI Wyoming. We refer to our general partner interest in OCI Wyoming as the "controlling interest" and to NRP's general partner interest as the "noncontrolling interest." Prior to this offering, the 1% limited partner interest in OCI Wyoming was held by OCI Wyoming Co., or Wyoming Co., an entity owned by OCI Holdings and NRP. References to our general partner refer to OCI Resource Partners LLC, or OCI GP, a wholly owned subsidiary of OCI Holdings. Please read "Summary—Formation Transactions and Partnership Structure."

         Unless the context otherwise requires, references in this prospectus to "the Company," "we," "our," "us," or like terms, when used in a historical context with respect to operations or assets, refer to OCI Wyoming. When used in a historical context with respect to financial results, such terms refer to OCI Holdings, or our "Predecessor," and, unless otherwised noted, financial information for our Predecessor is presented before the noncontrolling interest. When used in the present tense or prospectively, such terms refer to OCI Resources and its subsidiaries, and, unless otherwise noted, financial information for OCI Resources is presented before the noncontrolling interest. When we present financial information on a pro forma basis, such financial information assumes and gives effect to the consummation of this offering and the other transactions described under "Summary—Formation Transactions and Partnership Structure."

         OCI Resources does not have any employees, and we are managed by our general partner, the executive officers of which are employees of Enterprises. In this prospectus, we refer to Enterprises as our sponsor. Unless the context otherwise requires, references in this prospectus to "our officers" and "our directors" refer to the officers and directors of our general partner.

OCI Resources LP

Overview

        We are a Delaware limited partnership formed by OCI Holdings to operate the trona ore mining and soda ash production business of OCI Wyoming. We own a 50.5% controlling general partner interest and a 0.5% limited partner interest in OCI Wyoming, which is one of the largest and lowest cost producers of soda ash in the world, serving a global market from our facility in the Green River Basin of Wyoming. Our facility has been in operation for more than 50 years.

        As of March 31, 2013, OCI Wyoming had proven and probable reserves of approximately 267.1 million short tons of trona, which is equivalent to 145.5 million short tons of soda ash. During the

 

year ended December 31, 2012, OCI Wyoming mined approximately 3.87 million short tons of trona and produced approximately 2.45 million short tons of soda ash. During the three months ended March 31, 2013, OCI Wyoming mined approximately 1.0 million short tons of trona and produced approximately 0.63 million short tons of soda ash. Based on a projected mining rate of 4.0 million short tons of trona per year, OCI Wyoming has enough proven and probable trona reserves to continue mining trona for approximately 67 years.

        The following table sets forth certain operating data regarding our business.

		Year Ended December 31,									Three Months Ended March 31,
		2010			2011			2012			2012			2013
		(millions of short tons, except percentages and ratio data)
Trona ore mined			3.60			3.68			3.87			0.9			1.0
Operating rate(1)			97.6	%		98.6	%		98.6	%		97.7	%		95.4	%
Ore to ash ratio(2)			1.64:1.0			1.63:1.0			1.59:1.0			1.61:1.0			1.63:1.0
Soda ash volume sold			2.23			2.31			2.45			0.59			0.63

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(1)

Operating rate expresses the amount of soda ash produced in a given year as a percentage of our effective capacity for that year. Effective capacity reflects the volume of soda ash that we can produce using our current operational resources, taking into account scheduled and unscheduled downtime and idled capacity. We believe effective capacity is a more accurate measure of our potential output than nameplate capacity, which is theoretically the maximum volume of soda ash we could produce without any downtime or idled capacity.

(2)

Ore to ash ratio expresses the number of short tons of trona ore needed to produce one short ton of soda ash and includes our deca rehydration recovery process.

        Our facility is situated on approximately 880 acres, and our mining operations consist of approximately 23,500 acres of leased and licensed subsurface mining area. We use six large continuous mining machines and ten underground shuttle cars in our mining operations. Our processing assets consist of material sizing units, conveyors, calciners, dissolver circuits, thickener tanks, drum filters, evaporators and rotary dryers. Our facility also includes seven storage silos with total capacity of 65,000 short tons in which we store soda ash before shipment by bulk rail or truck to distributors and end customers. We lease a fleet of more than 1,700 covered hopper cars that serve as dedicated rail transport for approximately 98% of our soda ash.

        Trona, a naturally occurring soft mineral, is also known as sodium sesquicarbonate and consists primarily of sodium carbonate, or soda ash, sodium bicarbonate and water. We process trona ore into soda ash, which is an essential raw material in flat glass, container glass, detergents, chemicals, paper and other consumer and industrial products. The vast majority of the world's trona reserves are located in the Green River Basin. According to IHS Global Inc., or IHS, approximately one quarter of global soda ash is produced by processing trona, with the remainder being produced synthetically through chemical processes. We believe processing soda ash from trona is the cheapest manner in which to produce soda ash. The costs associated with procuring the materials needed for synthetic production are greater than the costs associated with mining trona for trona-based production. In addition, we believe trona-based production consumes less energy and produces fewer undesirable byproducts than synthetic production.

        For the year ended December 31, 2012, before the noncontrolling interest, pro forma total net sales, net income and Adjusted EBITDA were approximately $462.6 million, $114.1 million and $142.5 million, respectively. For the year ended December 31, 2012, after the noncontrolling interest, pro forma net income and Adjusted EBITDA were approximately $58.0 million and $72.7 million,

 

respectively. For the three months ended March 31, 2013, before the noncontrolling interest, pro forma total net sales, net income and Adjusted EBITDA were approximately $108.2 million, $17.2 million and $24.4 million, respectively. For the three months ended March 31, 2013, after the noncontrolling interest, pro forma net income and Adjusted EBITDA were approximately $8.2 million and $12.4 million, respectively. See "OCI Resources LP Unaudited Pro Forma Financial Statements" for details of pro forma adjustments made to prepare our pro forma financial statements before the noncontrolling interest. See "Selected Historical and Pro Forma Financial and Operating Data—Non-GAAP Financial Measures" for the definition of Adjusted EBITDA and a reconciliation of Adjusted EBITDA to net income and cash flow from operations.

Our Competitive Strengths

        We believe that the following competitive strengths will allow us to execute our business strategies successfully and to achieve our objective of generating and growing cash available for distribution to our unitholders:

        Cost Advantages of Producing Soda Ash from Trona.     We believe that as a producer of soda ash from trona, we have a significant competitive advantage compared to synthetic producers of soda ash. The manufacturing and processing costs for producing soda ash from trona are more cost competitive than other manufacturing techniques, partly because the costs associated with procuring the materials needed for synthetic production are greater than the costs associated with mining trona for trona-based production. In addition, we believe trona-based production consumes less energy and produces fewer undesirable byproducts than synthetic production. Based on our estimates and industry sources, we believe the average cost of production per short ton of soda ash (before freight and logistics costs) from trona is approximately one-third to one-half the cost per short ton of soda ash from synthetic production. We believe that our competitive cost structure, together with our current logistics arrangements, allows us to be competitive globally.

        Substantial Reserve Life from Significant Reserves.     As of March 31, 2013, we had approximately 128.8 million short tons of proven trona reserves and 138.3 million short tons of probable trona reserves as estimated by Hollberg Professional Group. Based on a mining rate of 4.0 million short tons of trona per year, we have enough proven and probable trona reserves to continue mining trona for approximately 67 years.

        Certain Operational Advantages Compared to Other Trona-Based Producers.     We believe we have certain operational advantages over other soda ash producers in the Green River Basin due to the operational characteristics of our facilities as described below. These advantages are manifested in our high productivity and efficiency rates.

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Location of our mining beds and high purity trona.   Our mining beds are located 800 to 1100 feet below the surface, which is significantly closer to the surface than the mining beds of other operators in the Green River Basin. The relatively shallow depth of our beds compared to other Green River Basin trona mines contributes to favorable ground conditions and improved mining efficiency. In addition, the trona in our mining beds has a higher concentration of soda ash as compared to the trona mined at other locations in the Green River Basin. Our trona ore is generally composed of approximately 85% to 89% pure trona.



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Advantageous facility layout.   Our surface site includes a high capacity network of natural ponds that we use to recapture soda ash lost in processing trona through a process we introduced in 2009 called deca rehydration. Primarily as a result of this process, we have been able to reduce our ore to ash ratio by 11% over the past three years. Introducing deca into our process has also reduced our energy consumption per short ton of soda ash produced.

 

        Strong Safety Record.     We have an outstanding track record for safety, and we have among the lowest instances of workplace injury in the U.S. mining industry. Our tradition of excellence in safety has been recognized by the Wyoming State Mine Inspector, which has awarded us its Safety Excellence Award for five consecutive years from 2008 to 2012. We also received three consecutive safety awards from the U.S. Industrial Minerals Association of North America and the Mine Safety and Health Administration from 2009 to 2011. In addition, the safety performance of our facilities, as measured by the number of citations, recordable injuries and lost work day injuries and accident incident rate, exceeds that of our peers in the Green River Basin over the last five years, according to the Mine Safety and Health Administration.

        Stable Customer Relationships.     We have an extensive base of over 75 customers in industries such as flat glass, container glass, detergents, chemicals, paper and other consumer and industrial products. We have long-term relationships with many of our customers due to our competitive pricing, reliable shipping and high quality soda ash. For the year ended December 31, 2012, approximately 70% of our domestic net sales were made to customers with whom we have done business for over ten years. We have a strong, long-standing relationship with our primary export customer, ANSAC. ANSAC is a cooperative that serves as the primary international distribution channel for us and two other U.S. manufacturers of trona-based soda ash. ANSAC is one of the largest purchasers and exporters of soda ash in the world, and, as a result, ANSAC is able to leverage its economies of scale in the markets it serves. We believe that our customer relationships, including our relationship with ANSAC, lead to more stable cash flows and allow us to plan production activity more accurately.

        Experienced Management and Workforce.     Our facility has been in continuous operation for over 50 years. We are able to build on the collective knowledge gained from our experience during this period to continually improve our operations and introduce innovative processes. In addition, many members of OCI Wyoming's senior management team have more than 20 years of relevant industry experience. Our executives lead a highly productive workforce with an average tenure of more than 18 years. We believe our institutional knowledge, coupled with the relative seniority of our workforce, engenders a strong sense of teamwork and collegiality, which has led to one of the safest and most efficient operations in the industry today.

Our Business Strategies

        Our primary business objective is to generate stable cash flows, allowing us to make quarterly cash distributions to our common and subordinated unitholders and, over time, to increase those quarterly cash distributions. To achieve our objective, we intend to execute the following key business strategies:

        Capitalize on the Growing Demand for Soda Ash.     We believe that as one of the leading low-cost producers of trona-based soda ash, we are well-positioned to capitalize on the worldwide growth of soda ash. While consumption of soda ash within the United States is expected to remain relatively stable in the near future, overall worldwide demand for soda ash is projected by IHS to grow from an estimated 59.4 million short tons in 2012 to approximately 82.3 million short tons by 2022, which represents a compounded annual growth rate of 3.4%. We believe that as global demand increases, we will be well positioned to maintain our market share in the principal markets in which we operate by increasing our production through refinements in our production process and without significant additional strategic capital expenditures.

        Increase Operational Efficiencies.     We intend to continue focusing on increasing the efficiency of our operations. More than $400 million in maintenance, efficiency and expansion related capital expenditures have been invested in OCI Wyoming since 1996. We have continued to improve our processing techniques, which have enabled us to reduce our ore to ash ratio by 11% over the past three years. We have identified opportunities to increase our annual production capacity by further streamlining our refining process and implementing certain process efficiencies. We anticipate that we

 

will spend approximately $22 million on these projects, which we expect will be completed by early 2015.

        Maintain Financial Flexibility.     We intend to pursue a disciplined financial policy and seek to maintain a conservative capital structure that we believe will provide enhanced stability to our existing cash flows and allow us to consider attractive growth projects and strategic acquisitions in all market environments. Upon the consummation of this offering, we expect OCI Wyoming's liquidity to consist of cash on hand and borrowing availability under a $190 million senior unsecured revolving credit facility, which we refer to as the OCI Wyoming Credit Facility. As of March 31, 2013, after giving effect to OCI Wyoming's entrance into the OCI Wyoming Credit Facility and borrowings of OCI Wyoming thereunder prior to the date of this prospectus, which borrowings have been or will be used to refinance $31.0 million of OCI Wyoming's existing debt, fund an $11.5 million special distribution to Wyoming Co. and a $91.5 million aggregate special distribution to OCI Holdings and NRP and pay approximately $1.2 million of debt issuance costs, OCI Wyoming's borrowing availability would have been $34.8 million under the OCI Wyoming Credit Facility. In addition, OCI Resources has $10 million of borrowing availability under its secured revolving credit facility, which we refer to as the Revolving Credit Facility. Please read "Management's Discussion and Analysis of Financial Condition and Results of Operations—Debt."

        Expand Operations Strategically.     In addition to capacity expansions and process improvements at our current facility, we plan to grow our business through various methods as they become available to us, including: (1) organic growth of our existing business by expanding our customer relationships and by making strategic capital expenditures; (2) acquisition of other businesses involved in mining and processing minerals and manufacturing chemicals; (3) acquisition of other soda ash facilities if and when they become available; and (4) acquisition of shipping, logistical or other ancillary businesses to improve our efficiencies and grow our cash flows. However, none of these opportunities may become available to us, and we may choose not to pursue any opportunities that are presented to us.