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The background of this research is the lack of technology-based learning materials, teachers, and students' need for the variety of new learning materials in SMP Negeri 1 Bantarkawung. This study aimed (1) to produce problem-based learning electronic student worksheets for number patterns and (2) to know the usefulness of problem-based learning electronic student worksheet for number patterns in terms of validity and practicality. It was the R&D (Research and Development) using ADDIE (Analyze, Design, Development, Implementation, and Evaluation) model. This research was conducted in class VIII A SMP Negeri 1 Bantarkawung involving six students in a small class trial and twenty-eight students in a big class trial. The research instruments were interview guidelines and questionnaires to material experts, media experts, and students' responses. The results showed that students' electronic worksheets were valid and practical. The evaluation by students' electronic worksheet material expert got 70,50, categorized as very valid. The review from media experts showed that Students' Electronic Worksheet got 68,50, which was classified as very valid. Meanwhile, the small class trial got 62,84, categorized as practical. Moreover, the big class trial got 65,39, and was classified as practical.

The education sector is feeling the impact of the COVID-19 pandemic. During the pandemic, the procedure for teaching and learning activities (TLA) changes according to the circumstances, this greatly affects the level of student learning activity (SLA). The purpose of this study is to improve SLA using the discovery learning mode (DLM) which is accompanied by the TPACK approach in mathematics teaching and learning. The type of research used is classroom action research (CAR), in this CAR it uses two cycles and each cycle has two meetings. This PTK takes the research subject, namely students of class X MIPA 2 SMAN 1 Bantul in the even semester of the 2021/2022 academic year. The results of this CAR show that there is an increase in SLA in mathematics learning using MDL. The increase in the SLA value can be seen from the pre-cycle results with the percentage value of 62.8% increasing to 71.42% after going through the action during the first cycle, then during the second cycle there was an increase with the percentage value of 89.7%. In cycle II, all SLA indicators have reached the desired criteria. The desired SLA criteria are with a minimum score percentage of 75% with high criteria.Keywords: discovery learning, Classroom Action Research, Student Learning Activity

Adanya kasus pandemic covid-19 mendesak pemerintah untuk merubah sistem pendidikan yang awalnya tatap muka menjadi tatap maya yang lebih dikenal dengan pembelajaran daring. Terlihat selama proses pembelajaran daring, motivasi belajar siswa menurun, terutama pada pembelajaran matematika. Penurunan motivasi belajar siswa ini juga terjadi di kelas X IPS 1 SMA Negeri 1 Bantul, Yogyakarta. Setelah dilakukan penyebaran angket motivasi belajar kepada siswa, kemudian dilakukan anaisis data,diperoleh skor rata-rata motivasi belajar siswa kelas X IPS 1 SMA Negeri 1 Bantul berada pada kategori sedang. Dari 32 siswa di kelas, terdapat 2 siswa dalam kategori sangat tinggi, 11 siswa dengan tingkat motivasi tinggi, dan 19 siswa dengan tingkat motivasi sedang. Tingkat motivasi belajar siswa dalam kategori sedang ini, terlihat dari terlihat dari kurangnya motivasi siswa dalam mengerjakan tugas yang diberikan guru selama pembelajaran daring. Selain itu pula, selama pembelajaran daring siswa cenderung tidak mau berusaha untuk menggali sendiri informasi terkait materi pembelajaran dan lebih suka menunggu materi dari guru.

One of the most widely used methods of survival analysis is Cox proportional hazard regression. It is a semiparametric regression used to investigate the effects of a number of variables on the dependent variable based on survival time. Using the Cox proportional hazard regression method, this study aims to estimate the factors that influence the survival of patients with type 2 diabetes mellitus. The estimated parameter values, as well as the Cox Regression equation model, were also investigated. A total of 1293 diabetic patients with type 2 diabetes were studied, with data taken from medical records at PKU Muhammadiyah Hospital in Yogyakarta, Indonesia. These variables have regression coefficients of 1.36, 1.59, -0.63, 0.11, and 0.51, respectively. Furthermore, the results showed the hazard ratio for female patients was 1.16 times male patients. Patients on insulin treatment had a 4.92-fold higher risk of death than those on other therapy profiles. Patients with normal blood sugar levels (GDS 140 mg/dl) had a 1.12 times higher risk of death than those with other blood glucose levels. Type 2 diabetes mellitus is a challenge for many Indonesians, in addition to being a deadly condition that was initially difficult to diagnose. As a result, patient survival analysis is needed to reduce the patient's risk of death.

Message security is must be managed seriously. Therefore, to maintain the confidentiality of any message, cryptography is needed. Cryptography is a science that uses mathematics to encrypt and decrypt messages. Cryptography is used as a tool to protect messages, for example, national secrets and strategies. The method of this research is qualitative research with a literature review. This research implements a hybrid cryptographic algorithm by combining Hill cipher and 3x3x3 Rubik's cube methods with Python software simulation.

Diberikan dan merupakan ring komutatif. Keprimaan pada suatu ring telah mengalami perkembangan ke dalam struktur modul. Namun, definisi keprimaan yang ada selama ini hanya berfokus pada operasi pergandaan skalar di dalam modul. Submodul prima-α merupakan salah satu perumuman dari submodul prima yang melibatkan operasi aditif dan pergandaan skalar di dalam modul. Pada artikel ini disajikan generalisasi dari submodul prima-α ke dalam struktur (R,S)-modul, yang selanjutnya disebut (R,S)-submodul prima-α gabungan. Selanjutnya, disajikan beberapa sifat dari (R,S)-submodul prima-α gabungan. Beberapa sifat tersebut diantaranya adalah syarat perlu dan syarat cukup suatu (R,S)-submodul membentuk (R,S)-submodul prima-α gabungan; sifat (R,S)-submodul prima-α gabungan yang berkaitan dengan homomorfisma (R,S)-modul; serta syarat perlu dan syarat cukup suatu (R,S)-submodul faktor membentuk (R,S)-submodul prima-α gabungan. Beberapa sifat (R,S)-submodul prima-α gabungan tersebut diperoleh dari pengembangan sifat keprimaan dalam struktur modul.

Perkembangan teknologi memberikan dampak terhadap kemajuan di segala bidang kehidupan manusia terutama dalam bidang informasi. Hal ini memberikan dampak positif dan negatif. Salah satu dampak positifnya adalah mudahnya bertukar informasi dari yang bersifat umum atau rahasia melalui internet. Dampak negatifnya adalah data yang bersifat rahasia menjadi kurang aman dan dapat disalahgunakan oleh pihak yang tidak berwenang. Kriptografi kurva eliptik El-Gamal (ECC: Eliptic Curve Cryptosystem) memberikan solusi untuk keamanan suatu informasi. ECC merupakan salah satu metode kriptografi kunci publik yang mempunyai tingkat keamanan tinggi dibandingkan dengan algoritma kunci publik lainnya. Tujuan dari penelitian ini adalah memahami konsep kriptografi kurva eliptik El-Gamal yang akan didefinisikan di Galois field prima. Hasil dari penelitian ini, yaitu penggunaan kurva eliptik El-Gamal di Galois field prima untuk proses pembentukan kunci, proses enkripsi dan proses dekripsi pada suatu data dengan menggunakan Python.

Let [Formula: see text] be a ring of the Morita context. We define a concept of Dubrovin valuation modules for bi-modules [Formula: see text] and [Formula: see text] and give necessary and sufficient conditions for [Formula: see text] to be a Dubrovin valuation ring in terms of [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text].

UDC 512.5Smith in paper [Mapping between module lattices, Int. Electron. J. Algebra, 15, 173–195 (2014)] introduced maps between the lattice of ideals of a commutative ring and the lattice of submodules of an -module i.e., and mappings.The definitions of the maps were motivated by the definition of multiplication modules.Moreover, some sufficient conditions for the maps to be a lattice homomorphisms are studied.In this work we define a class of -modules and observe the properties of the class. We give a sufficient conditions for the module and the ring such that the class is a hereditary pretorsion class.

In the development of Theory Radical of Rings, there are two kinds of radical constructions. The first radical construction is the lower radical construction and the second one is the upper radical construction. In fact, the class π of all prime rings forms a special class and the upper radical class of forms a radical class which is called the prime radical. An upper radical class which is generated by a special class of rings is called a special radical class. On the other hand, we also have the class of all semiprime rings which is weakly special class of rings. Moreover, we can construct a special class of modules by using a given special class of rings. This condition motivates the existence of the question how to construct weakly special class modules by using a given weakly special class of rings. This research is a qualitative research. The results of this research are derived from fundamental axioms and properties of radical class of rings especially on special and weakly special radical classes. In this paper, we introduce the notion of a weakly special class of modules, a generalization of the notion on a special class of modules based on the definition of semiprime modules. Furthermore, some properties and examples of weakly special classes of modules are given. The main results of this work are the definition of a weakly special class of modules and their properties.

Critical thinking skill was needed since problems in daily life required a solution. To solve the problems, the students collect the data as a consideration in making the right decision. Moreover, the students also need good critical thinking skills. To develop a good critical thinking skill, the researcher develops a textbook of Complex Analysis and Application, especially in complex numbers. In this research, a qualitative investigation was carried out in the development of the textbook. This textbook supports the mathematics education students of Universitas Ahmad Dahlan in learning complex analysis course. Researchers did a walkthrough to the expert in assessing the content and construct to validate the textbook. The development model used by researchers is a 4-D model. A 4-D model used in this study is consists of defining, designing, developing, and disseminating. In defining, the researcher adequate materials related to the complex numbers such as the rational number and real number and its properties in addition and multiplication. In designing, some explanation in the textbook is followed by Why and How questions. Open questions are used to stimulate the students’ critical thinking. Based on the walkthrough result, some notation in the textbook, especially mathematics symbols, must be revised using a proper mathematics equation. In addition, some concept should be clearly defined such as where the value of . As a result of the validity construct, the explanation given in the textbook used a step-by-step exercise. In disseminating, the students can easily access the textbook and answer the questions using their reasoning. The textbook is valid and readable.

The long-term objective of this research is to produce valid, practical, and effective textbooks for courses in international program of mathematics education of Universitas Ahmad Dahlan. For the short-term, this research aims to produce valid and practical textbook for number theory course. The validity was based on the relevancy towards the students’ expected competence, while the practicality was measured from the implementation of learning using the textbook. This research used design research with the type of development studies. It followed four steps, i.e. (1) preliminary research, (2) prototyping stage, (3) summative evaluation, and (4) systemic reflection and documentation. In the preliminary research, we analyzed the need of the textbook in the international program and found that the textbook of number theory course is very needed. In the prototyping stage, we wrote the textbook based on the need analysis. The prototype was then discussed with expert and revised in the stage of summative evaluation and applied to the lecture meetings. The result was the final product of the textbook used for the stage of systemic reflection and documentation when we wrote all the results according to the preset research framework. Finally, the developed number theory textbook is valid and practical.

One of Indonesian national education goals is to educate the intellectual life of the nation which is embodied in the preamble of the 1945 Constitution. Education plays a very central role to facilitate students to prepare the demands of science and technology advancement in the 21st century. To achieve these goals, education requires a powerful learning methods which can improve the positive attitude toward science of student from an early age. This study aims to determine the differences in attitude toward science between students in experimental group who received projects based learning and students who become the control group. This was quasy experimental research with Pretest-Postest Control Group Design. The populations were VIII graders in Malang city. The sampling was 54 student selected using purposive sampling. Instruments were validated by expert and tried out. The reliability coefficients for attitude toward science scale was 0,954. The results showed that attitude toward science students in experimental group who received projects based learning has significant difference with students in control group.

A ring A is called a *-ring if A is a prime ring and A has no nonzero proper prime homomorphic image. The *-ring was introduced by Korolczuk in 1981. Since *-rings have an important role in radical theory of rings, the properties of *-ring have been being investigated intensively. Since every ring can be viewed as a module over itself, the generalization of *-ring into module theory is an interesting investigation. We would like to present the generalization of *-rings in module theory named *p-modules. An A-module M is called a -module if M is a prime A-module and M has no nonzero proper prime submodule. According to the result of our investigation, we show that every *-ring is a *p-module over itself. Furthermore, let A be a ring, let M be an A-module, and let I be an ideal of A with I subset (0:M)A where (0:M)A={a in A| aM={0}}. We show that M is a *p-module over A if and only if M is a *p-module over A/I. On the other hand, the essential closure *k of the class of all *-rings is a special class of rings. As the last result of our investigation, we present the special class of modules determined by *k.

Mathematics literacy is individual capacity to formulate, to employ, and to interpret mathematics in various contexts. Indonesian students aged 15 are required to perform these three skills and these abilities reflect the success of the curriculum. The results, however, are never considered satisfying since, many argue, the students are not accustomed to deal with the mathematics literacy problems. Teacher is then the one who takes the responsibility to make the students familiar with the literacy problems. This research aims to look closer at the mathematics literacy skills possessed by pre-service teachers. It is a qualitative research which involved 128 undergraduate student teachers as the subjects. A custom mathematics literacy test was developed with various contexts to measure the student teachers’ literacy skills according to the PISA framework. The results suggest that they performed well in the level 1 to 3 problems, but not in the level 4 to 6. Many errors made by the student teachers in the stage of formulating, employing, or interpreting. Finally, teachers need to be accustomed to this skill before they are ready enough to teach their students.

Dalam perkembangan ilmu pengetahuan alam, matematika dan fisika merupakan ilmu-ilmu sains dasar yang merupakan fundamental bagi cabang ilmu yang lain. Dalam perkembangan ilmu Fisika seringkali juga memotivasi adanya temuan-temuan baru dalam ilmu matematika khususnya aljabar. Di lain pihak, banyak permasalahan dalam fisika teoritis dapat diselesaikan melalui pendekatan aljabar. Dalam kesempatan ini, salah satu bukti hubungan antara fisika dan matematika (khususnya aljabar) diberikan. Pada tahun 1967 suatu persamaan fundamental dalam Ilmu fisika ditemukan oleh penerima hadiah Nobel C. N. Yang. Dalam kurun waktu yang sama, persamaan ini juga diklaim ditemukan oleh R. J. Baxter. Oleh sebab itu, persamaan fundamental ini disebut dengan persamaan Yang-Baxter. Faktanya, persamaan Yang-Baxter ini mempunyai dampak besar dalam perkembangan ilmu pengetahuan, salah satunya adalah dalam Teori Knot. Akan tetapi solusi analitik dari persamaan ini belum ditemukan hingga saat ini. Hal ini memotivasi para peneliti untuk menemukan solusinya baik secara kualitatif maupun kuantitatif. Beberapa solusi pendekatan kualitatif telah ditemukan dengan menggunakan pendakatan struktur aljabar yang disebut dengan brace. Dalam paper ini, deskripsi tentang brace diberikan sebagai suatu perumuman dari radikal Jacobson dari suatu ring. Konstruksi brace dua sisi juga diberikan dalam artikel ini.

Let (X, ‖., .‖) be a non-Archimedean 2-normed spaces. In this paper, we construct p-summable vector-valued sequence spaces in non-Archimedean 2-normed spaces ℓ p (X) for 1 ≤ p ≤ ∞. Futhermore, we show that ℓ p (X) is a non-Archimedean 2-semi-normed spaces and we also give some inclusion relations on ℓ p (X).

Preface The Ahmad Dahlan International Conference on Mathematics and Mathematics Education, abbreviated as AD INTERCOMME, is a biennial international conference hosted in a cooperation by the Mathematics Department - Faculty of Science and Applied Technology - and the Mathematics Education Department - Faculty of Teacher Training and Education - of Universitas Ahmad Dahlan, Yogyakarta, Indonesia. It aims to provide a great forum for worldwide mathematicians, professors, teachers, and researchers to share their ideas about the trends and the emerging issues both in mathematics and mathematics education. In 2019, the AD INTERCOMME would be implemented for its second edition. We invite researchers and practitioners to come and to contribute in this conference. We would be very happy to welcome you in Yogyakarta. The keynote presentations are provided especially to show the contribution of Mathematician and Mathematics Educators in the world of mathematics and mathematics education towards research and knowledge sharing where our conference theme for this year is the contribution of Mathematics and Mathematics Education in Industrial Revolution Era 4.0. The main event is the talk of three keynote speakers. The first keynote speaker is Associate Professor Dr. Mazlini Adnan form Universiti Pendidikan Sultan Idris, Malaysia. The second keynote speaker is Associate Professor Martianus Frederick Ezerman, Ph.D from Nanyang Technological University, Singapore. The third keynote speaker is Associate Professor Dr. Sitti Maesuri Patahuddin from University of Canbera, Australia. We also have speakers in workshop session coming from Universitas Ahmad Dahlan, Dr. Rully Charitas Indra Prahmana, S.Si., M.Pd who deliver the talk on the Publishing Manuscripts in a Scopusindexed Journal and M. Rizky Alif Yuza who deliver the talk on the Workshop Big Data: “Sentiment Analysis Using Pyhton, Elastic Search and Kibana. ADINTERCOMME 2019 was an overwhelming success, attracting the delegates, speakers and sponsors from many countries and provided great intellectual and social interaction for the participants. Without their support, the conference would not have been successfully organized. We trust that all the participants found their involvement in the Conference both valuable and rewarding. Our wish is that all participants would enjoy this conference, contribute effectively toward it and take back with you knowledge, experiences, contacts and happy memories of this conference and especially with this beautiful kingdom of Yogyakarta. Dr. Puguh Wahyu Prasetyo, S.Si., M.Sc Editor in Chief

In the era of industrial revolution 4.0, many human activities depend on the gadget and the internet connection. We can observe the daily activities of human life right now. When they wake up in the morning, they usually start by using their handphones or gadget. This condition motivates educators to build a digital module in order to use the positive point of view of the Industry Revolution 4.0 era. In this chance, the researchers develop two topics that are very important for human life in Industry Revolution 4.0, whicht are, human literacy and technology literacy. Both of the topics were derived into two-courses. The course of development of students (Perkembangan Peserta Didik) will be representing the human literacy topics and the course of introduction to Biotechnology (pengantar bioteknologi) will be representing the technology literacy topic. The research is research and development. Furthermore, the products of this research are flipbooks that were uploaded on the Learning Management System managed by Universitas Ahmad Dahlan.

Olimpiade matematika merupakan salah satu ajang kompetisi yang dilaksanakan oleh pemerintah. Olimpiade matematika ini meliputi empat level yaitu tingkat sekolah dasar, sekolah menengah pertama, sekolah menengah atas, dan perguruan tinggi. Pelatihan yang diberikan kepada siswa cenderung hanya digunakan untuk sesaat persiapan olimpiade dan pada tahun berikutnya belum tentu siswa tersebut yang akan mewakili sekolah untuk mengikuti ajang olimpiade. Oleh sebab itu, pelatihan yang diberikan kepada guru lebih tepat. Dalam penelitian ini akan dibahas mengenai analisis keefektifan pelatihan yang diberikan kepada guru tingkat sekolah dasar Muhammadiyah se-Kota Yogyakarta yang membimbing siswa bidang matematika untuk berkompetisi di level olimpiade. Keefektifan pelatihan ini diukur dengan seberapa besar perubahan nilai rata-rata kemampuan guru dalam menyelesaikan soal olimpiade sebelum mendapatkan pelatihan dan setelah mendapatkan pelatihan.

The development of Ring Theory motivates the existence of the development of the Radical Theory of Rings. This condition is motivated since there are rings which have properties other than those owned by the set ring of all integers. These rings are collected so that they fulfill certain properties and they are called radical classes of rings. As the development of science about how to separate the properties of radical classes of rings motivates the existence of supernilpotent radical classes. On the other hand, there exists the concept of graded rings. This concept can be generalized into the Radical Theory of Rings. Thus, the properties of the graded supernilpotent radical classes are very interesting to investigate. In this paper, some graded supernilpotent radical of rings are given and their construction will be described. It follows from this construction that the graded Jacobson radical is a graded supernilpotent radical.

Let R and S be arbitrary rings. In the algebraic structure it is known that the R-module structure is a generalization of a vector space. As in the ring structure, in the R-module some previous researchers have defined R-module homomorphisms, the types of R-module homomorphisms, the properties of R-module homomorphisms, and the fundamental theorem of R-module isomorphisms. On the other hand, the R-module structure has been generalized to the (R, S)-module structure. However, research and discussion related to (R, S)-modules are still a bit worked out. Therefore, in this paper we present the definition of (R, S)-module homomorphisms, the types of (R, S)-module homomorphisms, the properties of (R, S)-module homomorphisms, and the fundamental theorem of (R, S)-module isomorphisms.

Prime essential ring and generalized prime essential rings can be used to determine whether a supernilpotent radical is a special radical. Special radical is one of the most important structure in the development of radical theory of rings. Since prime essential rings have an important role in radical theory of rings, we describe some properties of prime essential rings as well as their generalization. We show that every prime essential rings is a subdirectly reducible ring. Furthermore, the prime heart of prime essential ring is zero, so is the semiprime heart of prime an essential ring.

Let μ be a special class of rings, i.e. class of prime associative rings which is closed under ideals and essential extensions. Let *μ be the class of all *μ–rings, that is, rings in μ such that the factor ring is not in μ for every nonzero ideal of R. Apart from their interesting properties, *μ–rings from a generalization of the important class of *–rings introduced and studied in [4], [7], [8], and [14]. France-Jackson and Roux proved useful in describing minimal elements of lattices of hereditary radicals [9].It was observed in [9] that some special classes μ of rings, such as the class of all simple rings with unity, for example, coincide with *μ and the question was asked to describe all such special classes. We will give a partial answer to this question by noting that, in fact, this holds for every special class of simple rings with unity. However, the converse is not true.

Vector analysis is one of the cource listed in the curriculum of the Mathematics Education Department, Faculty of Education and Teacher Traning, Universitas Ahmad Dahlan. One of the factors which cause any difficulties and problems in learning Vector Analysis is the student literature used by almost all of the students. That student literature explained a ressume of materials in a brief way completed with many practises., that’s why, the student literature seems too mechanistics. Many student can not use it by theirselves, they need guidances to read that book. In order to solve that problem, teacher designed a student worksheet which is used by the students of the Vector Analysis course when the class is runing. The design of the student worksheet is a concept-based designed. The students can investigate some formulas during the learning of Vector Analysis by theirselves. On the other hand, students can solve some practises contained in the student worksheet easier since the practises is completed with the intructions step by step. During the cource of Vector Analysis, the given student worksheet has a positive response from the student based on the quetionnaire taken from the students. Around 69,2% of the students give their positive response to the student worksheet. The mean of the students score also increased from 60,3 to 80,1. This shows that using the student worksheet in Vector Analysis cource was very useful.

Telah dilakukan percobaan pemanggangan reduksi terhadap bijih nikel laterit kadar rendah jenis saprolit dari Sangaji Halmahera untuk bahan baku pembuatan Nickel Containing Pig Iron (NCPI/NPI). Percobaan ini dimaksudkan untuk mengetahui sampai sejauh mana terjadi peningkatan kadar Ni dan Fe dari saprolit kadar rendah dengan kadar 1,27 % Ni dan 9,44 % Fe. Pemanggangan reduksi terhadap pellet saprolit dilakukan dalam muffle furnace. Selanjutnya kalsin hasil reduksi dikonsentrasi menggunakan magnetik separator dengan cara basah untuk mendapatkan konsentrat dan tailing. Kemudian konsentrat dan tailing dianalisa dengan AAS untuk mengetahui seberapa besar peningkatan kadar Ni dan Fe. Untuk percobaan digunakan variabel temperatur, waktu dan persen reduktor. Diperoleh hasil percobaan optimal pada T ± 1100 ° C, bentonit 2 %, waktu pemanggangan 1 jam. dan 12,5 % batubara. Pada konsentrat terjadi peningkatan kadar Ni menjadi 1,97 % dan kadar Fe menjadi19,10 %. Sedangkan pada tailing terjadi penurunan kadar Ni menjadi 1,02 % dan kadar Fe naik menjadi 11,20%. Apabila konsentrat dilebur menjadi NCPI/NPI sesuai untuk menjadi SS 300 (stainless steel 300) sedangkan tailing apabila dilebur menjadi NCPI/NPI sesuai untuk menjadi SS 200. Abstract Reduction experiments have been conducted on the ore roasting of low grade nickel laterite saprolite type of Halmahera Sangaji feedstock for the manufacture of Pig Iron Containing Nickel (NCPI / NPI). These experiments are intended to determine the extent of an increase in levels of Ni and Fe from low grade saprolite grading 1.27% Ni and 9.44% Fe. Reduction roasting of pellets made in a Muffle Furnace saprolite. Further reduction results calcine concentrated using a magnetic separator with a wet method to get the concentrate and tailings. Then the concentrate and tailings were analyzed by Atomic Adsorption Spectrophotometry (AAS) to determine how much increased levels of Ni and Fe. For the experiments used a variable temperature, time and percent reducing agent. Optimal experimental results obtained at T ± 1100 °C, 2% bentonite, 1 hour roasting time. and 12.5% coal. At concentrations increased levels to 1.97% Ni and Fe levels to 19.10%. While the levels of Ni tailings decreased to 1.02% and Fe levels rose to 11. 20%. If the concentrate is melted into NCPI / NPI according to the SS 300 (stainless steel 300) while the tailings when merged into NCPI / NPI according to the SS 200.